October 2024
- NuFit-6.0: Updated global analysis of three-flavor neutrino oscillations
2410.05380 [abs] [pdf]
[abstract]
by Ivan Esteban, [and 5 more]M. C. Gonzalez-Garcia, Michele Maltoni, Ivan Martinez-Soler, João Paulo Pinheiro, and Thomas Schwetz [hide authors].
We present an updated global analysis of neutrino
oscillation data as of September 2024. The parameters
$\theta_{12}$, $\theta_{13}$, $\Delta m^2_{21}$, and $|\Delta m^2_{3\ell}|$
($\ell = 1,2$) are well-determined with relative precision at
$3\sigma$ of about 13\%, 8\%, 15\%, and 6\%, respectively. The
third mixing angle $\theta_{23}$ still suffers from the octant
ambiguity, with no clear indication of whether it is larger or
smaller than $45^\circ$. The determination of the leptonic CP phase
$\delta_{CP}$ depends on the neutrino mass ordering: for normal ordering
the global fit is consistent with CP conservation within $1\sigma$,
whereas for inverted ordering CP-violating values of $\delta_{CP}$ around
$270^\circ$ are favored against CP conservation at more than
$3.6\sigma$. While the present data has in principle
$2.5$--$3\sigma$ sensitivity to the neutrino mass ordering, there
are different tendencies in the global data that reduce the
discrimination power: T2K and NOvA appearance data individually
favor normal ordering, but they are more consistent with each other
for inverted ordering. Conversely, the joint determination of
$|\Delta m^2_{3\ell}|$ from global disappearance data prefers normal
ordering. Altogether, the global fit including long-baseline,
reactor and IceCube atmospheric data results into an almost equally
good fit for both orderings. Only when the $\chi^2$ table for
atmospheric neutrino data from Super-Kamiokande is added to our
$\chi^2$, the global fit prefers normal ordering with $\Delta\chi^2
= 6.1$. We provide also updated ranges and correlations for the
effective parameters sensitive to the absolute neutrino mass from
$\beta$-decay, neutrinoless double-beta decay, and cosmology.
- Neutrino Oscillations in Presence of Diagonal Elements of Scalar NSI: An
Analytic Approach
2410.05250 [abs] [pdf]
[abstract]
by Dharitree Bezboruah, [and 4 more]Dibya S. Chattopadhyay, Abinash Medhi, Arnab Sarker, and Moon Moon Devi [hide authors].
Scalar Non-Standard Interactions (SNSI) in neutrinos can arise when a scalar
mediator couples to both neutrinos and standard model fermions. This beyond the
Standard Model (BSM) scenario is particularly interesting as the SNSI
contribution appears as a density-dependent perturbation to the neutrino mass,
rather than appearing as a matter-induced potential, and the neutrino
oscillation probabilities uniquely depend on the absolute neutrino masses. In
this work, we show the complex dependence of the SNSI contributions on the
neutrino masses and discuss how the mass of the lightest neutrino would
regulate any possible SNSI contribution in both mass ordering scenarios. We
derive the analytic expressions for neutrino oscillation probabilities,
employing the Cayley-Hamilton theorem, in the presence of diagonal elements of
SNSI. The expressions are compact and shows explicit dependence on matter
effects and the absolute neutrino masses. The analytic expressions calculated
here allow us to obtain the dependence of the SNSI contribution on mass terms
of the form $m_1 + m_2$, $m_2 - m_1$, $m_1c_{12}^2 + m_2s_{12}^2,$ $
m_1s_{12}^2 + m_2c_{12}^2$, and $m_3$. We then explore the non-trivial impact
of neutrino mass ordering on the SNSI contribution. The dependence of the SNSI
contribution on the 3$\nu$ parameters is then thoroughly explored using our
analytic expressions.
- Measuring Solar neutrino Fluxes in Direct Detection Experiments in the
Presence of Light Mediators
2410.01167 [abs] [pdf]
[abstract]
by Shuo-yu Xia.
The potential of the dark matter direct detection experiments to provide
independent measurements on solar neutrino fluxes in the Standard Model and in
the presence of the light mediators is studied in this work. We also present
the sensitivity of direct detection experiments on light mediators with solar
neutrinos. We find that the sensitivities on $^8$B and pp neutrino fluxes can
reach $\pm10\%$ with improved backgrounds and systematic uncertainties and they
can be further pushed to $\pm3\%$ with a increased exposure. The constraints on
light mediators can reach $\mathcal{O}(10^{-6})$ for the masses of scalar and
vector mediators below 10 MeV. However, the presence of scalar or vector
mediators could lead to shifts in the best fit value of $^8$B fluxes, which
will increase the challenges in the precise measurements of solar neutrino
fluxes with direct detection experiments.
- Non-conservation of Lepton Numbers in the Neutrino Sector Could Change
the Prospects for Core Collapse Supernova Explosions
2410.01080 [abs] [pdf]
[abstract]
by Anna M. Suliga, [and 7 more]Patrick Chi-Kit Cheong, Julien Froustey, George M. Fuller, Lukáš Gráf, Kyle Kehrer, Oliver Scholer, and Shashank Shalgar [hide authors].
We show that strong interactions violating the conservation of lepton numbers
in the neutrino sector could significantly alter the standard low entropy
picture for the pre-supernova collapsing core of a massive star. A rapid
neutrino-antineutrino equilibration leads to entropy generation and enhanced
electron capture and, hence, a lower electron fraction than in the standard
model. This would affect the downstream core evolution, the prospects for a
supernova explosion, and the emergent neutrino signal. If realized by
lepton-number-violating neutrino self-interactions (LNV $\nu$SI), the relevant
mediator mass and coupling ranges can be probed by future accelerator-based
experiments.
- Enhancing DUNE's solar neutrino capabilities with neutral-current
detection
2410.00330 [abs] [pdf]
[abstract]
by Stephan A. Meighen-Berger, [and 4 more]Jayden L. Newstead, John F. Beacom, Nicole F. Bell, and Matthew J. Dolan [hide authors].
We show that the Deep Underground Neutrino Experiment (DUNE) has the
potential to make a precise measurement of the total active flux of 8B solar
neutrinos via neutral-current (NC) interactions with argon. This would
complement proposed precise measurements of solar-neutrino fluxes in DUNE via
charged-current (CC) interactions with argon and mixed CC/NC interactions with
electrons. Together, these would enable DUNE to make a SNO-like comparison of
rates and thus to make the most precise measurements of $\sin^2\theta_{12}$ and
$\Delta m^2_{21}$ using solar neutrinos. Realizing this potential requires
dedicated but realistic efforts to improve DUNE's low-energy capabilities and
separately to reduce neutrino-argon cross section uncertainties. Comparison of
mixing-parameter results obtained using solar neutrinos in DUNE and reactor
antineutrinos in JUNO (Jiangmen Underground Neutrino Observatory) would allow
unprecedented tests of new physics.
September 2024
- Looping Around Neutrino Charge Radius at Ultra-Near Reactor Experiments
2410.00107 [abs] [pdf]
[abstract]
by Vedran Brdar, [and 3 more]Leonardo J. Ferreira Leite, George A. Parker, and Xun-Jie Xu [hide authors].
We scrutinize the potential of upcoming ultra-near reactor neutrino
experiments to detect radiative corrections in the elastic neutrino-electron
scattering channel, focusing on the JUNO-TAO and CLOUD detectors, which employ
advanced scintillator detection technologies. Previous reactor experiments have
already constrained the electron neutrino charge radius, which is a neutrino
property associated with a certain subset of the total radiative corrections,
and have achieved limits that are only about an order of magnitude away from
the Standard Model prediction. Our study demonstrates that JUNO-TAO and CLOUD
could discover the neutrino charge radius in the near future, considering the
established treatment of the charge radius. However, we show that it is
necessary to go beyond this standard treatment. By including the complete set
of one-loop level radiative corrections, we find a partial cancellation with
the charge radius effect, reducing the experimental sensitivity to this
quantity. Nevertheless, JUNO-TAO and CLOUD still have the potential to achieve
a $5\sigma$ discovery but over longer timescales within a reasonable
operational timeframe.
- Sterile sector impacting the correlations and degeneracies among mixing
parameters at the Deep Underground Neutrino Experiment
2409.17878 [abs] [pdf]
[abstract]
by Sabila Parveen, [and 3 more]Mehedi Masud, Mary Bishai, and Poonam Mehta [hide authors].
We investigate the physics potential of the upcoming Deep Underground
Neutrino Experiment (DUNE) in probing active-sterile mixing. We present
analytic expressions for relevant oscillation probabilities for three active
and one sterile neutrino of eV-scale mass and highlight essential parameters
impacting the oscillation signals at DUNE. We then explore the space of sterile
parameters as well as study their correlations among themselves and with
parameters appearing in the standard framework ($\delta_{13}$ and
$\theta_{23}$). We perform a combined fit for the near and far detector at DUNE
using GLoBES. We consider alternative beam tune (low energy and medium energy)
and runtime combinations for constraining the sterile parameter space. We show
that charged current and neutral current interactions over the near and far
detector at DUNE allow for an improved sensitivity for a wide range of sterile
neutrino mass splittings.
- The cosmology of ultralight scalar dark matter coupled to right-handed
neutrinos
2409.17396 [abs] [pdf]
[abstract]
by Ryan Plestid and Sophia Tevosyan.
We consider ultralight scalar dark matter that couples to right-handed
neutrinos. Due to the high density of neutrinos in the early universe, the
background neutrino density dominates the dynamics of the scalar field, and
qualitatively alters the field's cosmological evolution. This effect has not
been included in previous literature, and changes the interpretation of
cosmological data and its interplay with laboratory experiments. To illustrate
these points a simplified model of a $1+1$ setup with a single scalar field is
analyzed.
We find that: {\it i}) The scalar field experiences an asymmetric potential
and its energy density redshifts differently than ordinary matter. {\it ii})
Neutrino mass measurements at the CMB and oscillation experiments performed
today complement one another (i.e., they constrain different regions of
parameter space). {\it iii}) There exists potentially interesting cosmologies
with either $O(1)$ variations in the dark matter density between the CMB and
today, or $O(1)$ oscillations of neutrino mass.
- The Unknowns of the Diffuse Supernova Neutrino Background Hinder New
Physics Searches
2409.16367 [abs] [pdf]
[abstract]
by Miller MacDonald, Pablo Martínez-Miravé, and Irene Tamborra.
Neutrinos traveling over cosmic distances are ideal probes of new physics. We
leverage on the approaching detection of the diffuse supernova neutrino
background (DSNB) to explore whether, if the DSNB showed departures from
theoretical predictions, we could attribute such modifications to new physics
unequivocally. In order to do so, we focus on visible neutrino decay. Many of
the signatures from neutrino decay are degenerate with astrophysical unknowns
entering the DSNB modeling. Next generation neutrino observatories, such as
Hyper-Kamiokande, JUNO, as well as DUNE, will set stringent limits on a
neutrino lifetime over mass ratio $\tau/m \sim 10^{9}$-$10^{10}$ s eV$^{-1}$ at
$90\%$ C.L., if astrophysical uncertainties and detector backgrounds were to be
fully under control. However, if the lightest neutrino is almost massless and
the neutrino mass ordering is normal, constraining visible decay will not be
realistically possible in the coming few decades. We also assess the challenges
of distinguishing among different new physics scenarios (such as visible decay,
invisible decay, and quasi-Dirac neutrinos), all leading up to similar
signatures in the DSNB. This work shows that the DSNB potential for probing new
physics strongly depends on an improved understanding of the experimental
backgrounds at next generation neutrino observatories as well as progress in
the DSNB modeling.
- Solar Neutrinos and the Strongest Oscillation Constraints on Scalar NSI
2409.15411 [abs] [pdf]
[abstract]
by Peter B. Denton, Alessio Giarnetti, and Davide Meloni.
Scalar non-standard neutrino interactions (sNSI) is a scenario where
neutrinos can develop a medium dependent contribution to their mass due to a
new scalar mediator. This scenario differs from the commonly discussed vector
mediator case in that the oscillation effect scales with density rather than
density and neutrino energy. Thus the strongest oscillation constraint comes
from solar neutrinos which experience the largest density in a neutrino
oscillation experiment. We derive constraints on all the sNSI parameters as
well as the absolute neutrino mass scale by combining solar and reactor data
and find solar neutrinos to be $>1$ order of magnitude more sensitive to sNSI
than terrestrial probes such as long-baseline experiments.
- Potential of Neutrino Telescopes to Detect Quantum Gravity-Induced
Decoherence in the Presence of Dark Fermions
2409.12633 [abs] [pdf]
[abstract]
by Alba Domi, [and 4 more]Thomas Eberl, Dominik Hellmann, Sara Krieg, and Heinrich Päs [hide authors].
We assess the potential of neutrino telescopes to discover
quantum-gravity-induced decoherence effects modeled in the open-quantum system
framework and with arbitrary numbers of active and dark fermion generations,
such as particle dark matter or sterile neutrinos. The expected damping of
neutrino flavor oscillation probabilities as a function of energy and
propagation length thus encodes information about quantum gravity effects and
the fermion generation multiplicity in the dark sector. We employ a public
Monte-Carlo dataset by the IceCube Collaboration to model the detector response
and estimate the sensitivity of IceCube to oscillation effects induced by the
presented model. Our findings confirm the potential of very-large-volume
neutrino telescopes to test this class of models and indicate higher
sensitivities for increasing numbers of dark fermions.
- Probing the cosmic sterile-neutrino background with IceCube
2409.12145 [abs] [pdf]
[abstract]
by Bhavesh Chauhan and Priyank Parashari.
In this paper, we take a close look at the interaction between the TeV--PeV
energy astrophysical neutrinos and a hypothetical cosmic sterile-neutrino
background. These interactions yield absorption features, also called ``dips",
in the astrophysical neutrino spectrum, which are studied using the deposited
energy distribution of high-energy starting events (HESE) in the IceCube
detector. We improve upon the previous analysis by including the effects of
regeneration and a realistic source distribution on the propagation of
astrophysical neutrinos. We use the latest 7.5-year HESE dataset and include
the observation of Glashow resonance in our analysis. We evaluate the impact of
these dips on the inferred spectral index and overall normalization of the
astrophysical neutrinos. We find a mild preference for dips in the 300--800 TeV
range, and the best-fit parameters for the mass of sterile-neutrino and the
mediator are 0.5 eV and 23 MeV, respectively. We find that the inclusion of
these absorption features lowers the spectral index of astrophysical neutrinos
to $2.60^{+0.19}_{-0.16}$. The lower spectral index can reduce the disagreement
with the Northern Tracks sample but requires dedicated analysis. We also
forecast the event spectrum for IceCube-Gen2 for the two different fits.
- On Precision of the Leptonic Mixing Angle $θ_{23}$ and its
Implications for the Flavor Models
2409.11824 [abs] [pdf]
[abstract]
by Son Cao, [and 4 more]P. T. Quyen, N. T. Hong Van, Ankur Nath, and T. V. Ngoc [hide authors].
Among three leptonic mixing angles, $\theta_{23}$ angle, which characterizes
the fractional contribution of two flavor eigenstates $\nu_{\mu}$ and
$\nu_{\tau}$ to the third mass eigenstate $\nu_3$, is known to be the largest
but the least precisely measured. The work investigates possible reach of
$\theta_{23}$ precision with two upcoming gigantic accelerator-based
long-baseline neutrino experiments, namely Hyper-Kamiokande and DUNE
experiments as well as a possible joint analyses of future neutrino facilities.
Our simulation yields that each experiment will definitely establish the octant
of $\theta_{23}$ angle for all values within 1$\sigma$ parameter interval,
while considering the current limitation. However, if the actual value is
$0.48\leq \sin^2\theta_{23}\leq 0.54$, it becomes challenging for these two
experiments to reject the maximal ($\theta_{23}=\pi/4$) hypothesis and conclude
its octant. This octant-blind region can be further explored with the proposed
facilities ESSnuSB and a neutrino factory. Accurate determination of the mixing
angle $\theta_{23}$, as well as the accuracy of $\delta_{CP}$, is crucial for
examining a certain category of discrete non-Abelian leptonic flavor models.
Specifically if CP is conserved in leptonic sector, the combined analysis of
Hyper-K and DUNE will rule out the majority of these models. However, if the CP
is maximally violated, higher precision of $\delta_{CP}$ is necessary for
testing these flavor models.
- Constraints on the maximal number of dark degrees of freedom from black
hole evaporation, cosmic rays, colliders, and supernovae
2409.11359 [abs] [pdf]
[abstract]
by Christopher Ewasiuk and Stefano Profumo.
A dark sector with a very large number of massive degrees of freedom is
generically constrained by radiative corrections to Newton's constant. However,
there are caveats to this statement, especially if the degrees of freedom are
light or mass-less. Here, we examine in detail and update a number of
constraints on the possible number of dark degrees of freedom, including from
black hole evaporation, from perturbations to systems including an evaporating
black hole, from direct gravitational production at colliders, from high-energy
cosmic rays, and from supernovae energy losses.
- High-Energy and Ultra-High-Energy Neutrinos from Primordial Black Holes
2409.09468 [abs] [pdf]
[abstract]
by Quan-feng Wu and Xun-Jie Xu.
Primordial Black Holes (PBHs) are capable of emitting extremely energetic
particles independent of their interactions with the Standard Model. In this
work, we investigate a particularly interesting scenario in which PBHs
evaporating in the early universe may be responsible for some of the observed
high-energy neutrinos above the TeV or PeV scale in the present universe. We
compute the energy spectrum of neutrinos directly emitted by PBHs with a
monochromatic mass function and estimate the wash-out point, which determines
the maximum energy of the spectrum. We find that the spectrum generally extends
to high energies following a power law of $E_{\nu}^{-3}$ until it reaches the
wash-out point, which crucially depends on the PBH mass. For PBHs of $10^{13}$
grams, the spectrum can extend up to the PeV scale, though the flux is too low
for detection. We also consider an indirect production mechanism involving dark
particles that are emitted by PBHs and decay into neutrinos at a much later
epoch. This mechanism allows lighter (such as those in the gram to kilogram
range) PBHs to produce more energetic neutrino fluxes without being washed out
by the thermal plasma in the early universe. In this scenario, we find that
ultra-high-energy neutrinos around or above the EeV scale can be generated,
with sufficiently high fluxes detectable by current and future high-energy
neutrino observatories such as IceCube and GRAND.
- Measuring the weak mixing angle at SBND
2409.07430 [abs] [pdf]
[abstract]
by Gustavo F. S. Alves, [and 4 more]Antonio P. Ferreira, Shirley Weishi Li, Pedro A. N. Machado, and Yuber F. Perez-Gonzalez [hide authors].
The weak mixing angle provides a sensitive test of the Standard Model. We
study SBND's sensitivity to the weak mixing angle using neutrino-electron
scattering events. We perform a detailed simulation, paying particular
attention to background rejection and estimating the detector response. We find
that SBND can provide a reasonable constraint on the weak mixing angle,
achieving 8% precision for $10^{21}$ protons on target, assuming an overall
flux normalization uncertainty of 10%. This result is superior to those of
current neutrino experiments and is relatively competitive with other
low-energy measurements.
- Constraints on neutrino non-standard interactions from COHERENT and
PandaX-4T
2409.04703 [abs] [pdf]
[abstract]
by Gang Li, [and 3 more]Chuan-Qiang Song, Feng-Jie Tang, and Jiang-Hao Yu [hide authors].
We investigate constraints on neutrino non-standard interactions (NSIs) in
the effective field theory framework, using data from the first measurement of
solar $^8$B neutrinos via coherent elastic neutrino-nucleus scattering
(CE$\nu$NS) in the PandaX-4T experiment and the COHERENT experiment. In the
PandaX-4T experiment, due to relatively large statistical uncertainties and
measured CE$\nu$NS counts that significantly differ from the Standard Model
predictions, its sensitivities to the neutrino NSIs are currently limited,
compared to the COHERENT experiment. However, the PandaX-4T experiment is
uniquely sensitive to the neutrino NSIs for the $\tau$ flavor due to
oscillation feature of the solar $^8$B neutrinos. We also assess how the
experimental central value, exposure, and systematic uncertainties will affect
the constraints on neutrino NSIs from various CE$\nu$NS measurements in the
future.
- FPF@FCC: Neutrino, QCD, and BSM Physics Opportunities with Far-Forward
Experiments at a 100 TeV Proton Collider
2409.02163 [abs] [pdf]
[abstract]
by Roshan Mammen Abraham, [and 9 more]Jyotismita Adhikary, Jonathan L. Feng, Max Fieg, Felix Kling, Jinmian Li, Junle Pei, Tanjona R. Rabemananjara, Juan Rojo, and Sebastian Trojanowski [hide authors].
Proton-proton collisions at energy-frontier facilities produce an intense
flux of high-energy light particles, including neutrinos, in the forward
direction. At the LHC, these particles are currently being studied with the
far-forward experiments FASER/FASER$\nu$ and SND@LHC, while new dedicated
experiments have been proposed in the context of a Forward Physics Facility
(FPF) operating at the HL-LHC. Here we present a first quantitative exploration
of the reach for neutrino, QCD, and BSM physics of far-forward experiments
integrated within the proposed Future Circular Collider (FCC) project as part
of its proton-proton collision program (FCC-hh) at $\sqrt{s} \simeq 100$ TeV.
We find that $10^9$ electron/muon neutrinos and $10^7$ tau neutrinos could be
detected, an increase of several orders of magnitude compared to (HL-)LHC
yields. We study the impact of neutrino DIS measurements at the FPF@FCC to
constrain the unpolarised and spin partonic structure of the nucleon and assess
their sensitivity to nuclear dynamics down to $x \sim 10^{-9}$ with neutrinos
produced in proton-lead collisions. We demonstrate that the FPF@FCC could
measure the neutrino charge radius for $\nu_{e}$ and $\nu_\mu$ and reach down
to five times the SM value for $\nu_\tau$. We fingerprint the BSM sensitivity
of the FPF@FCC for a variety of models, including dark Higgs bosons,
relaxion-type scenarios, quirks, and millicharged particles, finding that these
experiments would be able to discover LLPs with masses as large as 50 GeV and
couplings as small as $10^{-8}$, and quirks with masses up to 10 TeV. Our study
highlights the remarkable opportunities made possible by integrating
far-forward experiments into the FCC project, and it provides new motivation
for the FPF at the HL-LHC as an essential precedent to optimize the forward
physics experiments that will enable the FCC to achieve its full physics
potential.
- Implications of first neutrino-induced nuclear recoil measurements in
direct detection experiments
2409.02003 [abs] [pdf]
[abstract]
by D. Aristizabal Sierra, N. Mishra, and L. Strigari.
PandaX-4T and XENONnT have recently reported the first measurement of nuclear
recoils induced by the $^8$B solar neutrino flux, through the coherent elastic
neutrino-nucleus scattering (CE$\nu$NS) channel. As long anticipated, this is
an important milestone for dark matter searches as well as for neutrino
physics. This measurement means that these detectors have reached exposures
such that searches for low mass, $\lesssim 10$ GeV dark matter cannot be
analyzed using the background-free paradigm going forward. It also opens a new
era for these detectors to be used as neutrino observatories. In this paper we
assess the sensitivity of these new measurements to new physics in the neutrino
sector. We focus on neutrino non-standard interactions (NSI) and show that --
despite the still moderately low statistical significance of the signals --
these data already provide valuable information. We find that limits on NSI
from PandaX-4T and XENONnT measurements are comparable to those derived using
combined COHERENT CsI and LAr data, as well as those including the latest Ge
measurement. Furthermore, they provide sensitivity to pure $\tau$ flavor
parameters that are not accessible using stopped-pion or reactor sources. With
further improvements of statistical uncertainties as well as larger exposures,
forthcoming data from these experiments will provide important, novel results
for CE$\nu$NS-related physics.
- Deep Inelastic Scattering Cross Section Uncertainties in Tau Neutrino
Appearance Measurements
2409.01258 [abs] [pdf]
[abstract]
by Tetiana Kozynets, Thomas Stuttard, and D. Jason Koskinen.
In neutrino experiments sensitive to multiple flavors, the analyzers may be
presented with a choice of treating the uncertainties on the respective cross
sections in a correlated or an uncorrelated manner. This study focuses on the
charged current deep inelastic scattering (CC DIS) channel in experiments
sensitive to both muon and tau neutrinos. We evaluate the ratio of the
leading-order $\nu_{\tau}$ and $\nu_{\mu}$ cross sections and derive its
uncertainty from the underlying parton distribution functions (PDFs). We find
that, for neutrino energies above 5 GeV, the PDF-driven uncertainty on the
cross section ratio is less than 3%, with a larger (2-30%) variation seen in
antineutrinos at energies below 10 GeV. These results suggest that for
atmospheric tau neutrino appearance analyses, the uncertainties in $\nu_{\tau}$
and $\nu_{\mu}$ DIS cross sections should be coupled, while separate treatment
for the two flavors may be warranted in long-baseline experiments with an
antineutrino beam. We further explore the role of the invariant hadronic mass
threshold defining the onset of the DIS regime. We argue that its impact may be
incorporated only if it is applied to both DIS and resonance cross sections,
and if the correlations with other DIS and resonance cross section parameters
are taken into account.
August 2024
- Non-unitary limits on different textures for low-scale seesaw models
2408.13232 [abs] [pdf]
[abstract]
by Jesús Miguel Celestino-Ramírez, [and 3 more]G. Hernández-Tomé, O. G. Miranda, and Eduardo Peinado [hide authors].
New heavy neutral leptons lead to non-unitary effects in models for neutrino
masses. Such effects could represent a sign of new physics beyond the Standard
Model, leading to observable deviations in neutrino oscillation experiments,
lepton flavor violation, and other precision measurements. This work explores
the parameter space of the linear and inverse low-scale seesaw models based on
flavor symmetries consistent with neutrino oscillation experiments. In
particular, we investigated the violation of unitarity when the lepton flavor
violation is absent and when only one lepton flavor-violating channel is
present.
- Improved precision on 2-3 oscillation parameters using the synergy
between DUNE and T2HK
2408.12735 [abs] [pdf]
[abstract]
by Sanjib Kumar Agarwalla, Ritam Kundu, and Masoom Singh.
A high-precision measurement of $\Delta m^2_{31}$ and $\theta_{23}$ is
inevitable to estimate the Earth's matter effect in long-baseline experiments
which in turn plays an important role in addressing the issue of neutrino mass
ordering and to measure the value of CP phase in $3\nu$ framework. After
reviewing the results from the past and present experiments, and discussing the
near-future sensitivities from the IceCube Upgrade and KM3NeT/ORCA, we study
the expected improvements in the precision of 2-3 oscillation parameters that
the next-generation long-baseline experiments, DUNE and T2HK, can bring either
in isolation or combination. We highlight the relevance of the possible
complementarities between these two experiments in obtaining the improved
sensitivities in determining the deviation from maximal mixing of
$\theta_{23}$, excluding the wrong-octant solution of $\theta_{23}$, and
obtaining high precision on 2-3 oscillation parameters, as compared to their
individual performances. We observe that for the current best-fit values of the
oscillation parameters and assuming normal mass ordering (NMO), DUNE + T2HK can
establish the non-maximal $\theta_{23}$ and exclude the wrong octant solution
of $\theta_{23}$ at around 7$\sigma$ C.L. with their nominal exposures. We find
that DUNE + T2HK can improve the current relative 1$\sigma$ precision on
$\sin^{2}\theta_{23}~(\Delta m^{2}_{31})$ by a factor of 7 (5) assuming NMO.
Also, we notice that with less than half of their nominal exposures, the
combination of DUNE and T2HK can achieve the sensitivities that are expected
from these individual experiments using their full exposures. We also portray
how the synergy between DUNE and T2HK can provide better constraints on
($\sin^2\theta_{23}$ - $\delta_{\mathrm{CP}}$) plane as compared to their
individual reach.
- Neutrino Nonstandard Interactions and Lepton Flavor Universality
violation at SND@LHC via charm production
2408.11897 [abs] [pdf]
[abstract]
by Bhubanjyoti Bhattacharya, [and 5 more]Alakabha Datta, Elena Graverini, Lopamudra Mukherjee, Divya Sachdeva, and John Waite [hide authors].
In this work, we explore the effect of neutrino nonstandard interactions
(NSI) involving the charm quark at SND@LHC. Using an effective description of
new physics in terms of four-fermion operators involving a charm quark, we
constrain the Wilson coefficients of the effective interaction from two and
three-body charmed meson decays. In our fit, we include charmed meson decays
not only to pseudoscalar final states but also to vector final states and
include decays to the $\eta$ and $\eta^\prime$ final states. We also consider
constraints from charmed baryon decays. We then study the effect of new physics
in neutrino scattering processes, involving charm production at SND@LHC, for
various benchmark new physics couplings obtained from the low energy fits.
Finally, we also study the effects of lepton universality violation (LUV)
assuming that the new physics coupling is not lepton universal.
- Model-independent search for T violation with T2HK and DUNE
2408.06419 [abs] [pdf]
[abstract]
by Sabya Sachi Chatterjee, [and 3 more]Sudhanwa Patra, Thomas Schwetz, and Kiran Sharma [hide authors].
We consider the time reversal (T) transformation in neutrino oscillations in
a model-independent way by comparing the observed transition probabilities at
two different baselines at the same neutrino energy. We show that, under modest
model assumptions, if the transition probability $P_{\nu_\mu\to\nu_e}$ around
$E_\nu \simeq 0.86$ GeV measured at DUNE is smaller than the one at T2HK the T
symmetry has to be violated. Experimental requirements needed to achieve good
sensitivity to this test for T violation are to obtain enough statistics at
DUNE for $E_\nu \lesssim 1$ GeV (around the 2nd oscillation maximum), good
energy resolution (better than 10%), and near-detector measurements with a
precision of order 1% or better.
- Testing for coherence and nonstandard neutrino interactions in COHERENT
data
2408.06255 [abs] [pdf]
[abstract]
by Jiajun Liao, Danny Marfatia, and Jiajie Zhang.
We analyze data from the CsI, liquid Ar and Ge detectors of the COHERENT
experiment and confirm within $1.5\sigma$ that the measured elastic
neutrino-nucleus scattering cross section is proportional to the square of the
number of neutrons in the nucleus, as expected for coherent scattering in the
standard model. We also show how various degeneracies involving nonstandard
neutrino interaction parameters are broken in a combined analysis of the three
datasets.
- Cross Sections and Inelasticity Distributions of High-Energy Neutrino
Deep Inelastic Scattering
2408.05866 [abs] [pdf]
[abstract]
by Philip L. R. Weigel, Janet M. Conrad, and Alfonso Garcia-Soto.
This study presents a comprehensive model for neutrino deep inelastic
scattering (DIS) cross sections spanning energies from 50 GeV to
5$\times10^{12}$ GeV with an emphasis on applications to neutrino telescopes.
We provide calculations of the total charged-current DIS cross sections and
inelasticity distributions up to NNLO for isoscalar nucleon targets and up to
NLO order for nuclear targets. Several modifications to the structure functions
are applied to improve the modeling of the cross sections at low energies where
perturbative QCD is less accurate and at high energies where there is
non-negligible top quark production, and small-$x$ logarithms need to be
resumed. Using the FONLL general-mass variable-flavor number scheme, we account
for heavy quark mass effects and separate the heavy flavor components of the
structure functions, obtaining predictions of their relative contributions to
the cross sections and the uncertainties arising from the parton distribution
functions. Additionally, the effects of final state radiation are implemented
in the calculation of the double-differential cross section and discussed in
terms of their impact on measurements at neutrino telescopes.
- A Quantum Description of Wave Dark Matter
2408.04696 [abs] [pdf]
[abstract]
by Dhong Yeon Cheong, Nicholas L. Rodd, and Lian-Tao Wang.
We outline a fundamentally quantum description of bosonic dark matter (DM)
from which the conventional classical-wave picture emerges in the limit $m \ll
10~\textrm{eV}$. As appropriate for a quantum system, we start from the density
matrix which encodes the full information regarding the possible measurements
we could make of DM and their fluctuations. Following fundamental results in
quantum optics, we argue that for DM it is most likely that the density matrix
takes the explicitly mixed form of a Gaussian over the basis of coherent
states. Deviations from this would generate non-Gaussian fluctuations in DM
observables, allowing a direct probe of the quantum state of DM. Our quantum
optics inspired approach allows us to rigorously define and interpret various
quantities that are often only described heuristically, such as the coherence
time or length. The formalism further provides a continuous description of DM
through the wave-particle transition, which we exploit to study how density
fluctuations over various physical scales evolve between the two limits and to
reveal the unique behavior of DM near the boundary of the wave and particle
descriptions.
- Distinguishing Beyond-Standard Model Effects in Neutrino Oscillation
2408.04234 [abs] [pdf]
[abstract]
by A. Calatayud-Cadenillas, A. Pérez-G, and A. M. Gago.
We systematically assess the DUNE experiment's ability to distinguish between
various beyond-standard neutrino oscillation hypotheses pair combinations. For
a pair comparison, we evaluate the statistical separation, where one hypothesis
plays the role of the true signal while the other corresponds to the test
signal. The beyond-standard neutrino oscillation hypotheses under scrutiny
include neutrino decay (invisible and visible), non-standard interactions,
quantum decoherence, and the violation of the equivalence principle. When taken
as the true model, we found that either quantum decoherence or the violation of
the equivalence principle are the easiest to differentiate compared to the rest
of the hypotheses. Additionally, from our statistical test, we investigate
potential discrepancies between the measured CP-violation phase $\delta_{CP}$
relative to its true value, which could occur for a given comparison. In our
analysis, we will take the true values of $\delta_{CP}$ as $-90^\circ$ and
$180^\circ$. Notably, even in cases where the beyond-standard neutrino
oscillation hypotheses scenarios are statistically indistinguishable, the
measured value can exhibit significant deviations from its true value.
- Restricting Sterile Neutrinos by Neutrinoless Double Beta Decay
2408.01488 [abs] [pdf]
[abstract]
by Sudip Jana, Lucas Puetter, and Alexei Yu. Smirnov.
The bounds on parameters of the eV and higher scale sterile neutrinos from
the $0\nu \beta \beta$ decay have been refined and updated. We present a simple
and compact analytic expression for the bound in the $\Delta m^2_{41} - \sin^2
2\theta_{14}$ plane, which includes all relevant parameters. Dependencies of
the bound on unknown CP-phases and the type of mass spectrum of light neutrinos
(mass ordering and level of degeneracy) are studied in detail. We have computed
the bounds using the latest and most stringent data from KamLAND-Zen. The
projected constraints from future experiments are estimated. The obtained
bounds are confronted with positive indications of the presence of sterile
neutrinos as well as with the other existing bounds. The $0\nu \beta \beta$
decay results exclude the regions of parameters implied by BEST and Neutrino-4,
and the regions indicated by LSND and MiniBooNE are in conflict with $0\nu
\beta \beta$ results combined with $\nu_\mu-$ disappearance bounds.
- Old neutron stars as a new probe of relic neutrinos and sterile neutrino
dark matter
2408.01484 [abs] [pdf]
[abstract]
by Saurav Das, [and 3 more]P. S. Bhupal Dev, Takuya Okawa, and Amarjit Soni [hide authors].
We study the kinetic cooling (heating) of old neutron stars due to coherent
scattering with relic neutrinos (sterile neutrino dark matter) via Standard
Model neutral-current interactions. We take into account several important
physical effects, such as gravitational clustering, coherent enhancement,
neutron degeneracy and Pauli blocking. We find that the anomalous cooling of
nearby neutron stars due to relic neutrino scattering might actually be
observable by current and future telescopes operating in the optical to
near-infrared frequency band, such as the James Webb Space Telescope (JWST),
provided there is a large local relic overdensity that is still allowed.
Similarly, the anomalous heating of neutron stars due to coherent scattering
with keV-scale sterile neutrino dark matter, could also be observed by JWST or
future telescopes, which would probe hitherto unexplored parameter space in the
sterile neutrino mass-mixing plane.
July 2024
- Constraints on non-unitary neutrino mixing in light of atmospheric and
reactor neutrino data
2407.20388 [abs] [pdf]
[abstract]
by Tetiana Kozynets, [and 4 more]Philipp Eller, Alan Zander, Manuel Ettengruber, and D. Jason Koskinen [hide authors].
While the origin of neutrino masses remains unknown, several key neutrino
mass generation models result in a non-unitary three-neutrino mixing matrix. To
put such models to test, the deviations of the mixing matrix from unitarity can
be measured directly through neutrino oscillation experiments. In this study,
we perform a Bayesian analysis of the non-unitary mixing model using the recent
public data from atmospheric and reactor neutrino experiments - namely
IceCube-DeepCore, Daya Bay, and KamLAND. The novelty of our approach compared
to the preceding global fits for non-unitarity is in the detailed treatment of
the atmospheric neutrino data, which for the first time includes the relevant
flux and detector systematic uncertainties. From the Bayesian posteriors on the
individual mixing matrix elements, we derive the non-unitarity constraints in
the form of normalisations and closures of the mixing matrix rows and columns.
We find comparable constraints for electron and tau row normalisations as other
similar studies in literature, and additionally reveal strong correlations
between muon and tau row constraints induced by the atmospheric systematic
uncertainties. We find that the current data is well described by both unitary
and non-unitary mixing models, with a strong preference for the unitary mixing
indicated by the Bayes factor. With the upcoming IceCube-Upgrade and JUNO
detectors, both featuring superior energy resolution compared to the current
atmospheric and reactor neutrino experiments, our constraints on the row
normalisations are expected to improve by a factor of 2 (2.5) in the tau (muon)
sector and by nearly 25% in the electron sector. In the future, our approach
can be expanded to include solar and long-baseline neutrino experiments, with
the aim to provide more stringent constraints while keeping track of the
nuisance parameters that may be degenerate with non-unitarity.
- Do neutrinos bend? Consequences of an ultralight gauge field as dark
matter
2407.18300 [abs] [pdf]
[abstract]
by Luca Visinelli, Tsutomu T. Yanagida, and Michael Zantedeschi.
An ultralight gauge boson could address the missing cosmic dark matter, with
its transverse modes contributing to a relevant component of the galactic halo
today. We show that, in the presence of a coupling between the gauge boson and
neutrinos, these transverse modes affect the propagation of neutrinos in the
galactic core. Neutrinos emitted from galactic or extra-galactic supernovae
could be delayed by $\delta t = \left(10^{-8}-10^1\right)\,$s for the gauge
boson masses $m_{A'} = \left(10^{-23}-10^{-19}\right)\,$eV and the coupling
with the neutrino $g= 10^{-27}-10^{-20}$. While we do not focus on a specific
formation mechanism for the gauge boson as the dark matter in the early
Universe, we comment on some possible realizations. We discuss model-dependent
current bounds on the gauge coupling from fifth-force experiments, as well as
future explorations involving supernovae neutrinos. We consider the concrete
case of the DUNE facility, where the coupling can be tested down to $g \simeq
10^{-27}$ for neutrinos coming from a supernova event at a distance $d =
10\,$kpc from Earth.
- Exploring new physics with DUNE high energy flux: the case of Lorentz
Invariance Violation, Large Extra Dimensions and Long Range Forces
2407.17247 [abs] [pdf]
[abstract]
by Alessio Giarnetti, Simone Marciano, and Davide Meloni.
DUNE is a next-generation long-baseline neutrino oscillation experiment. It
is expected to measure with an unprecedent precision the atmospheric
oscillation parameters, including the CP-violating phase $\delta_{CP}$.
Moreover, several studies have suggested that its unique features should allow
DUNE to probe several new physics scenarios. In this work, we explore the
performances of the DUNE far detector in constraining new physics if a
high-energy neutrino flux is employed (HE-DUNE). We take into account three
different scenarios: Lorentz Invariance Violation (LIV), Long Range Forces
(LRF) and Large Extra Dimensions (LED). Our results show that HE-DUNE should be
able to set bounds competitive to the current ones and, in particular, it can
outperform the standard DUNE capabilities in constraining CPT-even LIV
parameters and the compactification radius $R_{ED}$ of the LED model.
- The case for adopting the sequential Jacobi's diagonalization algorithm
in neutrino oscillation physics
2407.17188 [abs] [pdf]
[abstract]
by Gustavo A. Valdiviesso.
Neutrino flavor oscillations and conversion in an interacting background (MSW
effects) may reveal the charge-parity violation in the next generation of
neutrino experiments. The usual approach for studying these effects is to
numerically integrate the Schrodinger equation, recovering the neutrino mixing
matrix and its parameters from the solution. This work suggests using the
classical Jacobi's diagonalization in combination with a reordering procedure
to produce a new algorithm, the Sequential Jacobi Diagonalization. This
strategy separates linear algebra operations from numerical integration,
allowing physicists to study how the oscillation parameters are affected by
adiabatic MSW effects in a more efficient way. The mixing matrices at every
point of a given parameter space can be stored for speeding up other
calculations, such as model fitting and Monte Carlo productions. This approach
has two major computation advantages, namely: being trivially parallelizable,
making it a suitable choice for concurrent computation, and allowing for
quasi-model-independent solutions that simplify Beyond Standard Model searches.
- A model for Axial Non-Standard Interactions of neutrinos with quarks
2407.13834 [abs] [pdf]
[abstract]
by S. Abbaslu and Yasaman Farzan.
The neutrino oscillation experiments are setting increasingly strong upper
bounds on the vectorial effective Non-Standard neutrino Interactions (NSI) with
matter fields. However, the bounds on the axial NSI are more relaxed, raising
the hope that studying the neutral current events at an experiment such as DUNE
can give a glimpse of new physics. We build a model that gives rise to axial
NSI with large couplings leading to observable deviation from the standard
prediction at DUNE. The model is based on a $U(1)$ gauge symmetry with a gauge
boson of mass $\sim 30$~GeV which can be discovered at the high luminosity LHC.
Combining the LHC and DUNE discoveries, we can unravel the axial form of
interaction. The cancellation of anomalies of the gauge group suggests new
heavy quarks as well as a dark matter candidate. The new quarks mixed with the
first generation quarks can also be discovered at the LHC. Moreover, they
provide a seesaw mechanism that explains the smallness of the $u$ and $d$ quark
masses. The dark matter has an axial coupling to the quarks which makes its
discovery via spin dependent direct dark matter search experiments possible.
- Dark photon distortions of NO$ν$A and T2K neutrino oscillations
2407.13817 [abs] [pdf]
[abstract]
by Gonzalo Alonso-Álvarez, [and 3 more]James M. Cline, Benoit Laurent, and Ushak Rahaman [hide authors].
Dark photons coupling to $L_\mu-L_\tau$ lepton number difference are a highly
studied light dark matter candidate, with potential to be discovered through
their impact on terrestrial neutrino oscillation experiments. We re-examine
this in the light of claimed tensions between the NO$\nu$A and T2K long
baseline experiments, also taking into account data from the MINOS experiment.
We obtain leading limits on the $L_\mu-L_\tau$ gauge coupling $g'$ versus dark
photon mass $m_{A'}$, and find no statistically significant alleviation of the
tension from inclusion of the new physics effect.
- First Indication of Solar $^8$B Neutrino Flux through Coherent Elastic
Neutrino-Nucleus Scattering in PandaX-4T
2407.10892 [abs] [pdf]
[abstract]
by PandaX Collaboration, [and 101 more]Zihao Bo, Wei Chen, Xun Chen, Yunhua Chen, Zhaokan Cheng, Xiangyi Cui, Yingjie Fan, Deqing Fang, Zhixing Gao, Lisheng Geng, Karl Giboni, Xunan Guo, Xuyuan Guo, Zichao Guo, Chencheng Han, Ke Han, Changda He, Jinrong He, Di Huang, Houqi Huang, Junting Huang, Ruquan Hou, Yu Hou, Xiangdong Ji, Xiangpan Ji, Yonglin Ju, Chenxiang Li, Jiafu Li, Mingchuan Li, Shuaijie Li, Tao Li, Zhiyuan Li, Qing Lin, Jianglai Liu, Congcong Lu, Xiaoying Lu, Lingyin Luo, Yunyang Luo, Wenbo Ma, Yugang Ma, Yajun Mao, Yue Meng, Xuyang Ning, Binyu Pang, Ningchun Qi, Zhicheng Qian, Xiangxiang Ren, Dong Shan, Xiaofeng Shang, Xiyuan Shao, Guofang Shen, Manbin Shen, Wenliang Sun, Yi Tao, Anqing Wang, Guanbo Wang, Hao Wang, Jiamin Wang, Lei Wang, Meng Wang, Qiuhong Wang, Shaobo Wang, Siguang Wang, Wei Wang, Xiuli Wang, Xu Wang, Zhou Wang, Yuehuan Wei, Weihao Wu, Yuan Wu, Mengjiao Xiao, Xiang Xiao, Kaizhi Xiong, Yifan Xu, Shunyu Yao, Binbin Yan, Xiyu Yan, Yong Yang, Peihua Ye, Chunxu Yu, Ying Yuan, Zhe Yuan, Youhui Yun, Xinning Zeng, Minzhen Zhang, Peng Zhang, Shibo Zhang, Shu Zhang, Tao Zhang, Wei Zhang, Yang Zhang, Yingxin Zhang, Yuanyuan Zhang, Li Zhao, Jifang Zhou, Jiaxu Zhou, Jiayi Zhou, Ning Zhou, Xiaopeng Zhou, Yubo Zhou, and Zhizhen Zhou [hide authors].
The PandaX-4T liquid xenon detector at the China Jinping Underground
Laboratory is used to measure the solar $^8$B neutrino flux by detecting
neutrinos through coherent scattering with xenon nuclei. Data samples requiring
the coincidence of scintillation and ionization signals (paired), as well as
unpaired ionization-only signals (US2), are selected with energy threshold of
approximately 1.1 keV (0.33 keV) nuclear recoil energy. Combining the
commissioning run and the first science run of PandaX-4T, a total exposure of
1.20 and 1.04 tonne$\cdot$year are collected for the paired and US2,
respectively. After unblinding, 3 and 332 events are observed with an
expectation of 2.8$\pm$0.5 and 251$\pm$32 background events, for the paired and
US2 data, respectively. A combined analysis yields a best-fit $^8$B neutrino
signal of 3.5 (75) events from the paired (US2) data sample, with $\sim$37\%
uncertainty, and the background-only hypothesis is disfavored at 2.64$\sigma$
significance. This gives a solar $^8$B neutrino flux of
($8.4\pm3.1$)$\times$10$^6$ cm$^{-2}$s$^{-1}$, consistent with the standard
solar model prediction. It is also the first indication of solar $^8$B neutrino
``fog'' in a dark matter direct detection experiment.
- Flavor-Specific Dark Matter Signatures through the Lens of Neutrino
Oscillations
2407.09614 [abs] [pdf]
[abstract]
by Subhaditya Bhattacharya, [and 3 more]Sven Fabian, Johannes Herms, and Sudip Jana [hide authors].
We investigate the flavor-specific properties of leptophilic dark matter in
neutrino mass models, where dark matter signals are directly correlated with
the neutrino oscillation data, providing complementary insights into the
neutrino mass hierarchy and CP phases. Notably, this can be accomplished
without introducing a flavor-specific portal to dark matter, imposing any new
flavor symmetry, or involving flavon fields. As a case study, we analyze the
correlation between the flavor-philic nature of dark matter and neutrino
oscillation data in the type-II seesaw and Zee-Babu models, and extend this
discussion to other neutrino mass models. We analyze the indirect signatures of
such leptophilic dark matter, specifically examining the spectrum of the cosmic
ray electron/positron flux resulting from the pair annihilation of dark matter
in the Galactic halo, and explore correlated lepton-specific signals at
collider experiments sensitive to neutrino oscillation data.
- Non-Standard Interactions of Supernova Neutrinos and Mass Ordering
Ambiguity at DUNE
2407.06251 [abs] [pdf]
[abstract]
by Sudip Jana and Yago Porto.
We show that non-standard neutrino interactions (NSI) can notably modify the
pattern of resonant flavor conversion of neutrinos within supernovae and
significantly impact the neutronization burst signal in forthcoming experiments
such as the Deep Underground Neutrino Experiment (DUNE). The presence of NSI
can invert the energy levels of neutrino matter eigenstates and even induce a
new resonance in the inner parts close to the proto-neutron star. We
demonstrate how DUNE can use these new configurations of energy levels to have
sensitivity to NSIs down to $\mathcal{O}(0.1)$. We also elucidate how the
effect may result in a puzzling confusion of normal and inverted mass orderings
by highlighting the emergence or vanishing of the neutronization peak, which
distinguishes between the two mass orderings. Potential implications are
analyzed thoroughly.
- T violation at a future neutrino factory
2407.05807 [abs] [pdf]
[abstract]
by Ryuichiro Kitano, Joe Sato, and Sho Sugama.
We study the possibility of measuring T (time reversal) violation in a future
long baseline neutrino oscillation experiment. By assuming a neutrino factory
as a staging scenario of a muon collider at the J-PARC site, we find that the
${\nu}_e \to {\nu}_{\mu}$ oscillation probabilities can be measured with a good
accuracy at the Hyper-Kamiokande detector. By comparing with the probability of
the time-reversal process, ${\nu}_{\mu} \to {\nu}_e$, measured at the T2K/T2HK
experiments, one can determine the CP phase $\delta$ in the neutrino mixing
matrix if $| \sin(\delta)|$ is large enough. The determination of $\delta$ can
be made with poor knowledge of the matter density of the earth as T violation
is almost insensitive to the matter effects. The comparison of CP and
T-violation measurements, ${\it \`a\ la}$ the CPT theorem, provides us with a
non-trivial check of the three neutrino paradigm based on the quantum field
theory.
- Helicity-changing Decays of Cosmological Relic Neutrinos
2407.04932 [abs] [pdf]
[abstract]
by Jihong Huang and Shun Zhou.
In this paper, we examine the possibility that massive neutrinos are unstable
due to their invisible decays $\nu^{}_i \to \nu^{}_j + \phi$, where $\nu^{}_i$
and $\nu^{}_j$ (for $i, j = 1, 2, 3$) are any two of neutrino mass eigenstates
with masses $m^{}_i > m^{}_j$ and $\phi$ is a massless Nambu-Goldstone boson,
and explore the implications for the detection of cosmological relic neutrinos
in the present Universe. First, we carry out a complete calculation of neutrino
decay rates in the general case where the individual helicities of parent and
daughter neutrinos are specified. Then, the invisible decays of cosmological
relic neutrinos are studied and their impact on the capture rates on the
beta-decaying nuclei (e.g., $\nu^{}_e + {^3{\rm H}} \to {^3{\rm He}} + e^-$) is
analyzed. The invisible decays of massive neutrinos could substantially change
the capture rates in the PTOLEMY-like experiments when compared to the case of
stable neutrinos. In particular, we find that the helicity-changing decays of
Dirac neutrinos play an important role whereas those of Majorana neutrinos have
no practical effects. However, if a substantial fraction of heavier neutrinos
decay into the lightest one, the detection of relic neutrinos will require a
much higher energy resolution and thus be even more challenging.
- $ν_μ$ and $ν_τ$ elastic scattering in Borexino
2407.03174 [abs] [pdf]
[abstract]
by Kevin J. Kelly, [and 3 more]Nityasa Mishra, Mudit Rai, and Louis E. Strigari [hide authors].
We perform a detailed study of neutrino-electron elastic scattering using the
mono-energetic $^{7}$Be neutrinos in Borexino, with an emphasis on exploring
the differences between the contributions of $\nu_e$, $\nu_\mu$, and
$\nu_\tau$. We find that current data are capable of measuring these components
such that the contributions from $\nu_\mu$ and $\nu_\tau$ cannot be zero,
although distinguishing between them is challenging -- the differences stemming
from Standard Model radiative corrections are insufficient without
significantly more precise measurements. In studying these components, we
compare predicted neutrino-electron scattering event rates within the Standard
Model (accounting for neutrino oscillations), as well as going beyond the
Standard Model in two ways. We allow for non-unitary evolution to modify
neutrino oscillations, and find that with a larger exposure (${\sim}30$x),
Borexino may provide relevant information for constraining non-unitarity, and
that JUNO may be able to accomplish this with its data collection of $^{7}$Be
neutrinos. We also consider novel $\nu_\mu$- and $\nu_\tau$-electron scattering
from a gauged $U(1)_{L_\mu - L_\tau}$ model, showing consistency with previous
analyses of Borexino and this scenario, but also demonstrating the impact of
uncertainties on Standard Model mixing parameters on these results.
- A Modern Look at the Oscillation Physics Case for a Neutrino Factory
2407.02572 [abs] [pdf]
[abstract]
by Peter B. Denton and Julia Gehrlein.
The next generation of neutrino oscillation experiments, JUNO, DUNE, and HK,
are under construction now and will collect data over the next decade and
beyond. As there are no approved plans to follow up this program with more
advanced neutrino oscillation experiments, we consider here one option that had
gained considerable interest more than a decade ago: a neutrino factory. Such
an experiment uses stored muons in a racetrack configuration with extremely
well characterized decays reducing systematic uncertainties and providing for
more oscillation channels. Such a machine could also be one step towards a high
energy muon collider program. We consider a long-baseline configuration to SURF
using the DUNE far detectors or modifications thereof, and compare the expected
sensitivities of the three-flavor oscillation parameters to the anticipated
results from DUNE and HK. We show optimal beam configurations, the impact of
charge identification, the role of statistics and systematics, and the expected
precision to the relevant standard oscillation parameters in different DUNE vs.
neutrino factory configurations.
- Dark Matter Raining on DUNE and Other Large Volume Detectors
2407.01670 [abs] [pdf]
[abstract]
by Javier F. Acevedo, Joshua Berger, and Peter B. Denton.
Direct detection is a powerful means of searching for particle physics
evidence of dark matter (DM) heavier than about a GeV with $\mathcal
O(kiloton)$ volume, low-threshold detectors. In many scenarios, some fraction
of the DM may be boosted to large velocities enhancing and generally modifying
possible detection signatures. We investigate the scenario where 100% of the DM
is boosted at the Earth due to new attractive long-range forces. This leads to
two main improvements in detection capabilities: 1) the large boost allows for
detectable signatures of DM well below a GeV at large-volume neutrino
detectors, such as DUNE, Super-K, Hyper-K, and JUNO, as possible DM detectors,
and 2) the flux at the Earth's surface is enhanced by a focusing effect. In
addition, the model leads to a significant anisotropy in the signal with the DM
flowing dominantly vertically at the Earth's surface instead of the typical
approximately isotropic DM signal. We develop the theory behind this model and
also calculate realistic constraints using a detailed GENIE simulation of the
signal inside detectors.
June 2024
- The $L_μ-L_τ$ solution to the IceCube UHE neutrino deficit in light
of NA64
2406.19968 [abs] [pdf]
[abstract]
by Leon M. G. de la Vega, Eduardo Peinado, and Jose Wudka.
In this work we analyze the scenario where a MeV scale $L_\mu - L_\tau$ gauge
boson can explain the deficit in the diffuse ultra high energy (UHE)
astrophysical neutrino spectrum observed in IceCube, as well as the discrepancy
between experimental and $e^+e^-$ dispersion data driven SM calculations of the
muon anomalous magnetic moment. We map the parameter space of the model where
the elastic resonant s-channel scattering of UHE neutrinos with the cosmic
neutrino background, mediated by the new Z', can improve the description of the
observed cascade and track spectra over the no-scattering hypothesis. Comparing
to recent NA64$\mu$ results, we find that some part of the parameter space
remains unexplored, but at a data volume of $10^{11}$ muons on target NA64$\mu$
will completely probe this region.
- Ultrahigh-energy neutrino searches using next-generation gravitational
wave detectors at radio neutrino detectors: GRAND, IceCube-Gen2 Radio, and
RNO-G
2406.19440 [abs] [pdf]
[abstract]
by Mainak Mukhopadhyay, [and 4 more]Kumiko Kotera, Stephanie Wissel, Kohta Murase, and Shigeo S. Kimura [hide authors].
Binary neutron star (BNS) mergers can be sources of ultrahigh-energy (UHE)
cosmic rays and potential emitters of UHE neutrinos. The upcoming and current
radio neutrino detectors like the Giant Radio Array for Neutrino Detection
(GRAND), IceCube-Gen2 Radio, and the Radio Neutrino Observatory in Greenland
(RNO-G) are projected to reach the required sensitivities to search for these
neutrinos. In particular, in conjunction with the next-generation of
gravitational wave (GW) detectors like Cosmic Explorer (CE) and Einstein
Telescope (ET), GW-triggered stacking searches can be performed with the UHE
neutrino detectors. In this work, we explore the prospects of such searches by
implementing in our analysis an upper distance limit based on the
sky-localization capabilities of the GW detectors from which meaningful
triggers can be collected. We find that if each GW burst is associated with a
total isotropic-equivalent energy of $\sim 10^{50} - 10^{51}$ erg emitted in
UHE neutrinos, along with a corresponding beaming fraction of $1$\%, GRAND and
IceCube-Gen2 Radio have a large probability ($\sim 99$\%) to detect a
coincident neutrino event using the joint combination of CE+ET in a timescale
of less than 15 years of operation for our fiducial choice of parameters. In
case of nondetections, the parameter spaces can be constrained at $3\sigma$
level in similar timescales of operation. We also highlight and discuss the
prospects of such joint radio neutrino detector network, their importance, and
their role in facilitating synergic GW and neutrino observations in the next
era of multimessenger astrophysics.
- Pseudo-Dirac Neutrinos and Relic Neutrino Matter Effect on the
High-energy Neutrino Flavor Composition
2406.18507 [abs] [pdf]
[abstract]
by P. S. Bhupal Dev, Pedro A. N. Machado, and Ivan Martinez-Soler.
We show that if neutrinos are pseudo-Dirac, they can potentially affect the
flavor ratio predictions for the high-energy astrophysical neutrino flux
observed by IceCube. In this context, we point out a novel matter effect
induced by the cosmic neutrino background (C$\nu$B) on the flavor ratio
composition. Specifically, the active-sterile neutrino oscillations over the
astrophysical baseline lead to an energy-dependent flavor ratio at Earth due to
the C$\nu$B matter effect, which is distinguishable from the vacuum oscillation
effect, provided there is a local C$\nu$B overdensity. Considering the
projected precision of the 3-neutrino oscillation parameter measurements and
improved flavor triangle measurements, we show that the next-generation
neutrino telescopes, such as IceCube-Gen2 and KM3NeT, can probe the
pseudo-Dirac neutrino hypothesis in a distinctive way.
- Impact of reactor neutrino uncertainties on coherent scattering's
discovery potential
2406.16081 [abs] [pdf]
[abstract]
by Leendert Hayen.
Nuclear power reactors are the most intense man-made source of antineutrino's
and have long been recognized as promising sources for coherent elastic
neutrino-nucleus scattering (CE$\nu$NS) studies. Its observation and the
spectral shape of the associated recoil spectrum is sensitive to a variety of
exotic new physics scenarios and many experimental efforts are underway. Within
the context of the reactor antineutrino anomaly, which initially indicated
eV-scale sterile neutrino's, the modeling of the reactor antineutrino spectrum
has seen a significant evolution in the last decade. Even so, uncertainties
remain due to a variety of nuclear structure effects, incomplete information in
nuclear databases and fission dynamics complexities. Here, we investigate the
effects of these uncertainties on one's ability to accurately distinguish new
physics signals. For the scenarios discussed here, we find that reactor
spectral uncertainties are similar in magnitude to the projected sensitivities
pointing towards a need for $\beta$ spectroscopy measurements below the inverse
$\beta$ decay threshold.
- The Sensitivity of DUNE in Presence of Off-Diagonal Scalar NSI
Parameters
2406.15307 [abs] [pdf]
[abstract]
by Arnab Sarker, [and 3 more]Dharitree Bezboruah, Abinash Medhi, and Moon Moon Devi [hide authors].
Scalar non-standard interactions (NSI) presents an exciting pathway for
probing potential new physics that extends beyond the Standard Model (BSM). The
scalar coupling of neutrinos with matter can appear as a sub-dominant effect
that can impact the neutrino oscillation probabilities. The uniqueness of these
interactions is that it can directly affect the neutrino mass matrix. This
makes oscillations sensitive to the absolute neutrino mass. The effects of
scalar NSI scales linearly with matter density which motivates its exploration
in long-baseline sector. The presence of scalar NSI can influence the key
measurements in the field of neutrino physics, including the precise
determination of the leptonic CP phase ($\delta_{CP}$), neutrino mass ordering
and the octant of $\theta_{23}$. The precise determination of $\delta_{CP}$ is
one of the major goals of DUNE, which is an upcoming long-baseline experiment.
A better understanding of the impact of scalar NSI on CP measurement
sensitivities is crucial for accurate interpretation of $\delta_{CP}$ phase. In
this work, we have explored the impact of the complex off-diagonal scalar NSI
elements $\eta_{\alpha\beta}$ and their associated phases $\phi_{\alpha\beta}$
on the CP-measurement sensitivities at DUNE. We have explored the impact of the
neutrino mass scale on these sensitivities. We look for constraining these
off-diagonal elements for different neutrino mass scales. We also explore their
correlation with $\delta_{CP}$, investigating potential degeneracies that can
arise due to additional phases. We also perform a correlation study among
different scalar NSI elements. We show that the inclusion of the complex scalar
NSI elements can significantly modify the CP phase measurements.
- First detection of coherent elastic neutrino-nucleus scattering on
germanium
2406.13806 [abs] [pdf]
[abstract]
by S. Adamski, [and 86 more]M. Ahn, P. S. Barbeau, V. Belov, I. Bernardi, C. Bock, A. Bolozdynya, R. Bouabid, J. Browning, B. Cabrera-Palmer, N. Cedarblade-Jones, J. Colón Rivera, E. Conley, V. da Silva, J. Daughhetee, J. Detwiler, K. Ding, M. R. Durand, Y. Efremenko, S. R. Elliott, A. Erlandson, L. Fabris, A. Galindo-Uribarri, M. P. Green, J. Hakenmüller, M. R. Heath, S. Hedges, H. Jeong, B. A. Johnson, T. Johnson, H. Jones, A. Khromov, A. Konovalov, E. Kozlova, A. Kumpan, O. Kyzylova, Y. Lee, G. Li, L. Li, J. M. Link, J. Liu, M. Luxnat, A. Major, K. Mann, D. M. Markoff, J. Mattingly, J. Moye, P. E. Mueller, J. Newby, N. Ogoi, J. O'Reilly, D. S. Parno, D. Pérez-Loureiro, D. Pershey, C. G. Prior, J. Queen, R. Rapp, H. Ray, O. Razuvaeva, D. Reyna, G. C. Rich, D. Rudik, J. Runge, D. J. Salvat, J. Sander, K. Scholberg, A. Shakirov, G. Simakov, W. M. Snow, V. Sosnovtsev, M. Stringer, T. Subedi, B. Suh, B. Sur, R. Tayloe, K. Tellez-Giron-Flores, Y. -T. Tsai, E. E. van Nieuwenhuizen, C. J. Virtue, G. Visser, K. Walkup, E. M. Ward, T. Wongjirad, Y. Yang, J. Yoo, C. -H. Yu, and A. Zaalishvili [hide authors].
We report the first detection of coherent elastic neutrino-nucleus scattering
(CEvNS) on germanium, measured at the Spallation Neutron Source at Oak Ridge
National Laboratory. The Ge-Mini detector of the COHERENT collaboration employs
large-mass, low-noise, high-purity germanium spectrometers, enabling excellent
energy resolution, and an analysis threshold of 1.5 keV electron-equivalent
ionization energy. We observe a on-beam excess of 20.6$_{+7.1}^{-6.3}$ counts
with a total exposure of 10.22 GWhkg and we reject the no-CEvNS hypothesis with
3.9 sigma significance. The result agrees with the predicted standard model of
particle physics signal rate within 2 sigma.
- Neutrino Tomography of the Earth: the Earth Total Mass, Moment of
Inertia and Hydrostatic Equilibrium Constraints
2406.13727 [abs] [pdf]
[abstract]
by S. T. Petcov.
We investigate the implications of the constraints following from the precise
knowledge of the total Earth mass, $M_\oplus$, and moment of inertia,
$I_\oplus$, and from the requirement that Earth be in hydrostatic equilibrium
(EHE), in the neutrino tomography studies of the Earth density structure. In
order to estimate the sensitivity of a given neutrino detector to possible
deviations of the inner core (IC), outer core (OC), core (IC + OC) and mantle
Earth densities from those obtained using geophysical and seismological data
and described by the preliminary reference Earth model (PREM), in the
statistical analyses performed within the neutrino tomography studies one
typically varies the density of each of these structures. These variations,
however, must respect the $M_\oplus$, $I_\oplus$ and EHE constraints. Working
with PREM average densities we derive the $M_\oplus$, $I_\oplus$ and EHE
constraints on the possible density variations when one approximates the Earth
density structure with i) three layers - mantle, outer core and inner core, and
ii) four layers - upper mantle, lower mantle, outer core and inner core. We get
drastically different results in the two cases.
- Direct neutrino-mass measurement based on 259 days of KATRIN data
2406.13516 [abs] [pdf]
[abstract]
by M. Aker, [and 148 more]D. Batzler, A. Beglarian, J. Behrens, J. Beisenkötter, M. Biassoni, B. Bieringer, Y. Biondi, F. Block, S. Bobien, M. Böttcher, B. Bornschein, L. Bornschein, T. S. Caldwell, M. Carminati, A. Chatrabhuti, S. Chilingaryan, B. A. Daniel, K. Debowski, M. Descher, D. Díaz Barrero, P. J. Doe, O. Dragoun, G. Drexlin, F. Edzards, K. Eitel, E. Ellinger, R. Engel, S. Enomoto, A. Felden, C. Fengler, C. Fiorini, J. A. Formaggio, C. Forstner, F. M. Fränkle, K. Gauda, A. S. Gavin, W. Gil, F. Glück, S. Grohmann, R. Grössle, R. Gumbsheimer, N. Gutknecht, V. Hannen, L. Hasselmann, N. Haußmann, K. Helbing, H. Henke, S. Heyns, S. Hickford, R. Hiller, D. Hillesheimer, D. Hinz, T. Höhn, A. Huber, A. Jansen, C. Karl, J. Kellerer, K. Khosonthongkee, M. Kleifges, M. Klein, J. Kohpeiß, C. Köhler, L. Köllenberger, A. Kopmann, N. Kovač, A. Kovalík, H. Krause, L. La Cascio, T. Lasserre, J. Lauer, T. Le, O. Lebeda, B. Lehnert, G. Li, A. Lokhov, M. Machatschek, M. Mark, A. Marsteller, E. L. Martin, C. Melzer, S. Mertens, S. Mohanty, J. Mostafa, K. Müller, A. Nava, H. Neumann, S. Niemes, A. Onillon, D. S. Parno, M. Pavan, U. Pinsook, A. W. P. Poon, J. M. Lopez Poyato, S. Pozzi, F. Priester, J. Ráliš, S. Ramachandran, R. G. H. Robertson, C. Rodenbeck, M. Röllig, C. Röttele, M. Ryšavý, R. Sack, A. Saenz, R. Salomon, P. Schäfer, M. Schlösser, K. Schlösser, L. Schlüter, S. Schneidewind, U. Schnurr, M. Schrank, J. Schürmann, A. Schütz, A. Schwemmer, A. Schwenck, M. Šefčík, D. Siegmann, F. Simon, F. Spanier, D. Spreng, W. Sreethawong, M. Steidl, J. Štorek, X. Stribl, M. Sturm, N. Suwonjandee, N. Tan Jerome, H. H. Telle, L. A. Thorne, T. Thümmler, S. Tirolf, N. Titov, I. Tkachev, K. Urban, K. Valerius, D. Vénos, C. Weinheimer, S. Welte, J. Wendel, C. Wiesinger, J. F. Wilkerson, J. Wolf, S. Wüstling, J. Wydra, W. Xu, S. Zadorozhny, and G. Zeller [hide authors].
The fact that neutrinos carry a non-vanishing rest mass is evidence of
physics beyond the Standard Model of elementary particles. Their absolute mass
bears important relevance from particle physics to cosmology. In this work, we
report on the search for the effective electron antineutrino mass with the
KATRIN experiment. KATRIN performs precision spectroscopy of the tritium
$\beta$-decay close to the kinematic endpoint. Based on the first five
neutrino-mass measurement campaigns, we derive a best-fit value of $m_\nu^{2} =
{-0.14^{+0.13}_{-0.15}}~\mathrm{eV^2}$, resulting in an upper limit of $m_\nu <
{0.45}~\mathrm{eV}$ at 90 % confidence level. With six times the statistics of
previous data sets, amounting to 36 million electrons collected in 259
measurement days, a substantial reduction of the background level and improved
systematic uncertainties, this result tightens KATRIN's previous bound by a
factor of almost two.
- Impacts of Black-Hole-Forming Supernova Explosions on the Diffuse
Neutrino Background
2406.13276 [abs] [pdf]
[abstract]
by Ken'ichiro Nakazato, [and 3 more]Ryuichiro Akaho, Yosuke Ashida, and Takuji Tsujimoto [hide authors].
Flux spectrum, event rate, and experimental sensitivity are investigated for
the diffuse supernova neutrino background (DSNB), which is originated from past
stellar collapses and also known as supernova relic neutrino background. For
this purpose, the contribution of collapses that lead to successful supernova
(SN) explosion and black hole (BH) formation simultaneously, which are
suggested to be a non-negligible population from the perspective of Galactic
chemical evolution, is taken into account. If the BH-forming SNe involve the
matter fallback onto the protoneutron star for the long term, their total
emitted neutrino energy becomes much larger than that of ordinary SNe and
failed SNe (BH formation without explosion). The expected event rate according
to the current DSNB model is enhanced by up to a factor of two due to the
BH-forming SNe, depending on their fraction and the neutrino mass hierarchy. In
any case, the operation time required to detect the DSNB at Hyper-Kamiokande
would be reduced by such contribution.
- Getting More Out of Black Hole Superradiance: a Statistically Rigorous
Approach to Ultralight Boson Constraints
2406.10337 [abs] [pdf]
[abstract]
by Sebastian Hoof, [and 4 more]David J. E. Marsh, Júlia Sisk-Reynés, James H. Matthews, and Christopher Reynolds [hide authors].
Black hole (BH) superradiance can provide strong constraints on the
properties of ultralight bosons (ULBs). Since most of the previous work has
focused on the theoretical predictions, here we investigate the most suitable
statistical framework to constrain ULB masses and self-interactions. We argue
that a Bayesian approach provides a clear statistical interpretation, deals
with limitations regarding the reproducibility of existing BH analyses,
incorporates the full information from BH data, and allows us to include
additional nuisance parameters or to perform hierarchical modelling with BH
populations in the future. We demonstrate the feasibility of our approach using
mass and spin posterior samples for the X-ray binary BH M33 X-7 and, for the
first time in this context, the supermassive BH IRAS 09149-6206. We explain the
differences to existing ULB constraints in the literature and illustrate the
effects of various assumptions about the superradiance process (equilibrium
regime vs cloud collapse, higher occupation levels). As a result, our procedure
yields the most rigorous ULB constraints available in the literature, with
important implications for the QCD axion and axion-like particles. We encourage
all groups analysing BH data to publish likelihood functions or posterior
samples as supplementary material to facilitate this type of analysis.
- Decaying sterile neutrinos at short baselines
2406.04401 [abs] [pdf]
[abstract]
by Matheus Hostert, Kevin J. Kelly, and Tao Zhou.
Long-standing anomalous experimental results from short-baseline neutrino
experiments have persisted for decades. These results, when interpreted with
one or more light sterile neutrinos, are inconsistent with numerous null
results experimentally. However, if the sterile neutrino decays en route to the
detector, this can mimic $\nu_\mu \to \nu_e$ oscillation signals while avoiding
many of these external constraints. We revisit this solution to the MiniBooNE
and LSND puzzles in view of new data from the MicroBooNE experiment at
Fermilab. Using MicroBooNE's liquid-argon time-projection chamber search for an
excess of $\nu_e$ in the Booster beam, we derive new limits in two models'
parameter spaces of interest: where the sterile neutrino decays (I) via mixing
with the active neutrinos, or (II) via higher-dimensional operators. We also
provide an updated, comprehensive fit to the MiniBooNE neutrino- and
antineutrino-beam data, including appearance ($\nu_e$) and disappearance
($\nu_\mu$) channels. Despite alleviating the tension with muon neutrino
disappearance experiments, we find that the latest MicroBooNE analysis rules
out the decaying sterile neutrino solution in a large portion of the parameter
space at more than $99\%$ CL.
- Effects of Neutrino-Ultralight Dark Matter Interaction on the Cosmic
Neutrino Background
2406.01682 [abs] [pdf]
[abstract]
by Pablo Martínez-Miravé, Yuber F. Perez-Gonzalez, and Manibrata Sen.
Ultralight dark matter interacting with sterile neutrinos would modify the
evolution and properties of the cosmic neutrino background through
active-sterile neutrino mixing. We investigate how such an interaction would
induce a redshift dependence in neutrino masses. We highlight that cosmological
constraints on the sum of neutrino masses would require reinterpretation due to
the effective mass generated by neutrino-dark matter interactions. Furthermore,
we present an example where such interactions can alter the mass ordering of
neutrinos in the early Universe, compared to what we expect today. We also
address the expected changes in the event rates in a PTOLEMY-like experiment,
which aims to detect the cosmic neutrino background via neutrino capture, and
discuss projected constraints.
- Mapping the sources of CP violation in neutrino oscillations from the
seesaw mechanism
2406.01142 [abs] [pdf]
[abstract]
by Zhi-zhong Xing.
We present the first complete calculation of the Jarlskog invariant, a
working measure of the strength of CP violation in the flavor oscillations of
three light neutrino species, with the help of a full Euler-like block
parametrization of the flavor structure in the canonical seesaw mechanism. We
find that this invariant depends on 240 linear combinations of the 6 original
phase parameters that are responsible for CP violation in the decays of three
heavy Majorana neutrinos in 27 linear combinations as a whole, and thus
provides the first model-independent connection between the microscopic and
macroscopic matter-antimatter asymmetries.
- High-energy Neutrino Source Cross-correlations with Nearest Neighbor
Distributions
2406.00796 [abs] [pdf]
[abstract]
by Zhuoyang Zhou, [and 3 more]Jessi Cisewski-Kehe, Ke Fang, and Arka Banerjee [hide authors].
The astrophysical origins of the majority of the IceCube neutrinos remain
unknown. Effectively characterizing the spatial distribution of the neutrino
samples and associating the events with astrophysical source catalogs can be
challenging given the large atmospheric neutrino background and underlying
non-Gaussian spatial features in the neutrino and source samples. In this
paper, we investigate a framework for identifying and statistically evaluating
the cross-correlations between IceCube data and an astrophysical source catalog
based on the $k$-Nearest Neighbor Cumulative Distribution Functions
($k$NN-CDFs). We propose a maximum likelihood estimation procedure for
inferring the true proportions of astrophysical neutrinos in the point-source
data. We conduct a statistical power analysis of an associated likelihood ratio
test with estimations of its sensitivity and discovery potential with synthetic
neutrino data samples and a WISE-2MASS galaxy sample. We apply the method to
IceCube's public ten-year point-source data and find no statistically
significant evidence for spatial cross-correlations with the selected galaxy
sample. We discuss possible extensions to the current method and explore the
method's potential to identify the cross-correlation signals in data sets with
different sample sizes.
- Muon neutrinos and the cosmological abundance of primordial black holes
2406.00664 [abs] [pdf]
[abstract]
by Jiali Hao, [and 4 more]Yupeng Yang, Qianyong Li, Yankun Qu, and Shuangxi Yi [hide authors].
In the mixed dark matter scenarios consisting of primordial black holes
(PBHs) and particle dark matter (DM), PBHs can accrete surrounding DM particles
to form ultracompact minihalos (UCMHs or clothed PBHs) even at an early epoch
of the Universe. The distribution of DM particles in a UCMH follows a steeper
density profile compared with a classical DM halo. It is expected that the DM
annihilation rate is very large in UCMHs, resulting in a contribution to, e.g.,
the extragalactic neutrino flux. In this work, we investigate the extragalactic
neutrino flux from clothed PBHs due to DM annihilation, and then the muon flux
for neutrino detection. Compared with the atmospheric neutrino flux, we derive
the upper limits on the cosmological abundance of PBHs for 10 years of exposure
time of, e.g., the IceCube experiment. Compared with other constraints,
although the upper limits obtained by us are not the strongest, it is a
different way to study the cosmological abundance of PBHs.
May 2024
- The flavor invariants of the $ν$SM
2406.00094 [abs] [pdf]
[abstract]
by Christophe Grojean, [and 3 more]Jonathan Kley, Damien Leflot, and Chang-Yuan Yao [hide authors].
Sixty years after the experimental discovery of CP violation in the quark
sector, the existence of a similar CP violation in the lepton sector is still
to be established. Actually, the structure of such a violation depends
crucially on the origin of the neutrino masses. In an attempt at categorizing
the leptonic sources of CP violation, we studied the $\nu$SM, the Standard
Model extended with three generations of sterile neutrinos, that can
interpolate continuously between the Dirac and Majorana scenarios of neutrino
masses. In particular, we perform a classification of the Jarlskog-like flavor
invariants entering CP-violating observables and we study their suppression
with the heavy Majorana mass in the seesaw limit of the model. To simplify the
construction of the invariants, we introduce a graph-based method. With the
guidance of the Hilbert series and plethystic logarithm of the theory, we
construct the \emph{generating} and \emph{primary} sets of invariants for the
$\nu$SM for the first time. Unlike in the Standard Model and some other
theories, we find that the numbers of generating invariants and the syzygies
among them cannot immediately be read off from the plethystic logarithm, but
require a more careful examination. Our analysis reveals that the
\emph{generating} set contains 459 invariants, out of which 208 are CP-even and
251 are CP-odd. In the seesaw limit of the $\nu$SM, we show that all parameters
of the UV theory can be captured in the effective theory with a certain
suppression with the heavy Majorana mass, while these parameters can only
appear in a \emph{flavor-invariant} way with a \emph{higher} mass suppression.
Furthermore, we discuss how the necessary and sufficient conditions for CP
violation can be captured by utilizing these invariants. Along the way, we
present useful algorithms to enumerate and build the flavor invariants.
- Diffuse Boosted Cosmic Neutrino Background
2405.14946 [abs] [pdf]
[abstract]
by Gonzalo Herrera, Shunsaku Horiuchi, and Xiaolin Qi.
Energetic cosmic rays scatter off the cosmic neutrino background throughout
the history of the Universe, yielding a diffuse flux of cosmic relic neutrinos
boosted to high energies. We calculate this flux under different assumptions of
the cosmic-ray flux spectral slope and redshift evolution. The non-observation
of the diffuse flux of boosted relic neutrinos with current high-energy
neutrino experiments already excludes an average cosmic neutrino background
overdensity larger than $\sim 10^{4}$ over cosmological distances. We discuss
the future detectability of the diffuse flux of boosted relic neutrinos in
light of neutrino overdensity estimates and cosmogenic neutrino backgrounds.
- New limits on neutrino decay from high-energy astrophysical neutrinos
2405.14826 [abs] [pdf]
[abstract]
by Victor B. Valera, [and 3 more]Damiano F. G. Fiorillo, Ivan Esteban, and Mauricio Bustamante [hide authors].
Since neutrinos have mass differences, they could decay into one another. But
their lifetimes are likely long, even when shortened by new physics, so decay
likely impacts neutrinos only during long trips. This makes high-energy
astrophysical neutrinos, traveling for up to billions of light-years, sensitive
probes of decay. However, their sensitivity must be tempered by reality. We
derive from them thorough bounds on the neutrino lifetimes accounting for
critical astrophysical unknowns and the nuances of neutrino detection. Using
the diffuse neutrino flux, we disfavor lifetimes $\tau \lesssim 20$-450 s
$(m/{\rm eV})$, based on present IceCube data, and forecast factor-of-10
improvements by upcoming detectors. Using, for the first time, neutrinos from
the active galaxy NGC 1068, extant unknowns preclude placing lifetime bounds
today, but upcoming detectors could disfavor $\tau \sim 100$-5000 s $(m/{\rm
eV})$.
- Resonant Neutrino Flavor Conversion in the Atmosphere
2405.12140 [abs] [pdf]
[abstract]
by Connor Sponsler, [and 3 more]Matheus Hostert, Ivan Martinez-Soler, and Carlos A. Argüelles [hide authors].
Neutrinos produced in the atmosphere traverse a column density of air before
being detected at neutrino observatories like IceCube or KM3NeT. In this work,
we extend the neutrino flavor evolution in the {nuSQuIDS} code accounting for
the varying height of neutrino production and the variable air density in the
atmosphere. These effects can lead to sizeable spectral distortions in standard
neutrino oscillations and are crucial to accurately describe some new physics
scenarios. As an example, we study a model of quasi-sterile neutrinos that
induce resonant flavor conversions at neutrino energies of ${O}(300)\text{
MeV}$ in matter densities of $1 \text{ g/cm}^3$. In atmospheric air densities,
the same resonance is then realized at neutrino energies of ${O}(300-
700)$~GeV. We find that the new resonance can deplete the $\nu_\mu +
\overline{\nu}_\mu$ flux at the IceCube Neutrino Observatory by as much as
$10\%$ in the direction of the horizon.
- Limits on the parameter space of (3+2) sterile neutrino scenario by
IceCube data
2405.10419 [abs] [pdf]
[abstract]
by Emilse Cabrera, Arman Esmaili, and Alexander A. Quiroga.
The neutrino sector of the standard model of particles can contain more than
one sterile neutrino states. Generally, existence of more sterile states leads
to better, or at least equally good, fit to the short baseline anomalous data
due to the larger number of parameters and interferences which create features
in the oscillation pattern. However, for experiments like IceCube, where the
sterile states distort the oscillation pattern of high energy atmospheric
neutrinos through parametric and MSW resonances, addition of more sterile
states leads to a more intense effect. Although the limits on one additional
sterile neutrino state by IceCube data have been studied in the literature,
bounds on the models with more sterile states are lacking. We analyze the
one-year data set of atmospheric neutrinos collected by IceCube during the
2011-2012 and derive the limits on the parameter space of (3+2) scenario with
two sterile neutrino states, taking into account the relevant systematic and
statistical uncertainties and atmospheric neutrino flux variants. To facilitate
the joint analysis of IceCube and short baseline data, we provide the table of
$\chi^2$ values from IceCube's data analysis as function of the parameters.
- Revisiting Reactor Anti-Neutrino 5 MeV Bump with $^{13}$C
Neutral-Current Interaction
2405.08724 [abs] [pdf]
[abstract]
by Pouya Bakhti, [and 4 more]Min-Gwa Park, Meshkat Rajaee, Chang Sub Shin, and Seodong Shin [hide authors].
For the first time, we systematically investigate the potential of
neutrino-nucleus neutral current interactions with $^{13}$C to identify the
origin of the 5 MeV bump observed in reactor anti-neutrino spectra in the
inverse beta decay process. The distinctive signal is obtained from the
de-excitation of $^{13}$C$^*$ into the ground state emitting a 3.685 MeV photon
in various liquid scintillator detectors. Such an interaction predominantly
occurs for the reactor anti-neutrinos within the energy range coinciding with
the 5 MeV bump. For a detector that has a capability of 95\% level photon and
electron separation and small thorium contamination below $5 \times 10^{-17}$
gr/gr located in a site with an overburden of about a few hundred m.w.e, such
as the location of near detectors of RENO and Daya Bay will have a great
sensitivity to resolve the 5 MeV bump. In addition, we propose a novel approach
to track the time evolution of reactor isotopes by analyzing our $^{13}$C
signal shedding light on the contributions from $^{235}$U or $^{239}$Pu to the
observed bump. This provides an extra powerful tool in both discriminating the
flux models and testing any new physics possibilities for the 5 MeV bump at
3$\sigma$ to 5$\sigma$ level with much less systematic uncertainties and
assuming 10 kt.year of data collection. Our detector requirements are
realistic, aligning well with recent studies conducted for existing or
forthcoming experiments.
- Neutrino Oscillations as a Gravitational Wave Detector?
2405.05000 [abs] [pdf]
[abstract]
by Dominik Hellmann, [and 3 more]Sara Krieg, Heinrich Päs, and Mustafa Tabet [hide authors].
Gravitational Waves (GWs) can alter the neutrino propagation distance and
thus affect neutrino oscillations. This can result in a complete disappearance
of the oscillatory behavior that competes with other sources of neutrino
decoherence. We develop a set of criteria that determines under which
conditions neutrino oscillations are sensitive to this effect, and discuss
three concrete scenarios for neutrinos from astrophysical sources. We find that
neutrino oscillations may probe so far unexplored regions of the GW parameter
space.
- Fast and Accurate Algorithm for Calculating Long-Baseline Neutrino
Oscillation Probabilities with Matter Effects: NuFast
2405.02400 [abs] [pdf]
[abstract]
by Peter B. Denton and Stephen J. Parke.
Neutrino oscillation experiments will be entering the precision era in the
next decade with the advent of high statistics experiments like DUNE, HK, and
JUNO. Correctly estimating the confidence intervals from data for the
oscillation parameters requires very large Monte Carlo data sets involving
calculating the oscillation probabilities in matter many, many times. In this
paper, we leverage past work to present a new, fast, precise technique for
calculating neutrino oscillation probabilities in matter optimized for
long-baseline neutrino oscillations in the Earth's crust including both
accelerator and reactor experiments. For ease of use by theorists and
experimentalists, we provide fast c++ and fortran codes.
- No $ν$s is Good News
2405.00836 [abs] [pdf]
[abstract]
by Nathaniel Craig, [and 3 more]Daniel Green, Joel Meyers, and Surjeet Rajendran [hide authors].
The baryon acoustic oscillation (BAO) analysis from the first year of data
from the Dark Energy Spectroscopic Instrument (DESI), when combined with data
from the cosmic microwave background (CMB), has placed an upper-limit on the
sum of neutrino masses, $\sum m_\nu < 70$ meV (95%). In addition to excluding
the minimum sum associated with the inverted hierarchy, the posterior is peaked
at $\sum m_\nu = 0$ and is close to excluding even the minumum sum, 58 meV at
2$\sigma$. In this paper, we explore the implications of this data for
cosmology and particle physics. The sum of neutrino mass is determined in
cosmology from the suppression of clustering in the late universe. Allowing the
clustering to be enhanced, we extended the DESI analysis to $\sum m_\nu < 0$
and find $\sum m_\nu = - 160 \pm 90$ meV (68%), and that the suppression of
power from the minimum sum of neutrino masses is excluded at 99% confidence. We
show this preference for negative masses makes it challenging to explain the
result by a shift of cosmic parameters, such as the optical depth or matter
density. We then show how a result of $\sum m_\nu =0$ could arise from new
physics in the neutrino sector, including decay, cooling, and/or time-dependent
masses. These models are consistent with current observations but imply new
physics that is accessible in a wide range of experiments. In addition, we
discuss how an apparent signal with $\sum m_\nu < 0$ can arise from new long
range forces in the dark sector or from a primordial trispectrum that resembles
the signal of CMB lensing.
April 2024
- Impact of recent updates to neutrino oscillation parameters on the
effective Majorana neutrino mass in 0$νββ$ Decay
2404.19624 [abs] [pdf]
[abstract]
by Dongming Mei, [and 3 more]Kunming Dong, Austin Warren, and Sanjay Bhattarai [hide authors].
We investigate how recent updates to neutrino oscillation parameters and the
sum of neutrino masses influence the sensitivity of neutrinoless double-beta
(0$\nu\beta\beta$) decay experiments. Incorporating the latest cosmological
constraints on the sum of neutrino masses and laboratory measurements on
oscillations, we determine the sum of neutrino masses for both the normal
hierarchy (NH) and the inverted hierarchy (IH). Our analysis reveals a narrow
range for the sum of neutrino masses, approximately 0.06 eV/c$^2$ for NH and
0.102 eV/c$^2$ for IH. Utilizing these constraints, we calculate the effective
Majorana masses for both NH and IH scenarios, establishing the corresponding
allowed regions. Importantly, we find that the minimum neutrino mass is
non-zero, as constrained by the current oscillation parameters. Additionally,
we estimate the half-life of 0$\nu\beta\beta$ decay using these effective
Majorana masses for both NH and IH. Our results suggest that upcoming ton-scale
experiments will comprehensively explore the IH scenario, while 100-ton-scale
experiments will effectively probe the parameter space for the NH scenario,
provided the background index can achieve 1 event/kton-year in the region of
interest.
- Testing the Origins of Neutrino Mass with Supernova Neutrino Time Delay
2404.17352 [abs] [pdf]
[abstract]
by Shao-Feng Ge, Chui-Fan Kong, and Alexei Y. Smirnov.
The origin of neutrino masses remains unknown. Both the vacuum mass and the
dark mass generated by the neutrino interactions with DM particles or fields
can fit the current oscillation data. The dark mass squared is proportional to
the DM number density and therefore varies on the galactic scale with much
larger values around the Galactic Center. This affects the group velocity and
the arrival time delay of core-collapse supernovae neutrinos. This time delay,
especially for the $\nu_e$ neutronization peak with a sharp time structure, can
be used to distinguish the vacuum and dark neutrino masses. For illustration,
we explore the potential of DUNE which is sensitive to $\nu_e$. Our simulations
show that DUNE can distinguish the two neutrino mass origins at more than
$5\sigma\,$C.L., depending on the observed local value of neutrino mass, the
neutrino mass ordering, the DM density profile, and the SN location.
- A Mass Ordering Sum Rule for the Neutrino Disappearance Channels in T2K,
NOvA and JUNO
2404.08733 [abs] [pdf]
[abstract]
by Stephen J. Parke and Renata Zukanovich Funchal.
We revisit a method for determining the neutrino mass ordering by using
precision measurements of the atmospheric $\Delta m^2$'s in both electron
neutrino and muon neutrino disappearance channels, proposed by the authors in
2005 (hep-ph/0503283). The mass ordering is a very important outstanding
question for our understanding of the elusive neutrino and determination of the
mass ordering has consequences for other neutrino experiments. The JUNO reactor
experiment will start data taking this year, and the precision of the
atmospheric $\Delta m^2$'s from electron anti-neutrino measurements will
improve by a factor of three from Daya Bay's 2.4 % to 0.8 % within a year. This
measurement, when combined with the atmospheric $\Delta m^2$'s measurements
from T2K and NOvA for muon neutrino disappearance, will contribute
substantially to the $\Delta \chi^2$ between the two remaining neutrino mass
orderings. In this paper we derive a mass ordering sum rule that can be used to
address the possibility that JUNO's atmospheric $\Delta m^2$'s measurement,
when combined with other experiments in particular T2K and NOvA, can determine
the neutrino mass ordering at the 3 $\sigma$ confidence level within one year
of operation. For a confidence level of 5 $\sigma$ in a single experiment we
will have to wait until the middle of the next decade when the DUNE experiment
is operating.
- Constraining solar electron number density via neutrino flavor data at
Borexino
2404.06468 [abs] [pdf]
[abstract]
by Caroline Laber-Smith, [and 8 more]Eve Armstrong, A. Baha Balantekin, Elizabeth K. Jones, Lily Newkirk, Amol V. Patwardhan, Sarah Ranginwala, M. Margarette Sanchez, and Hansen Torres [hide authors].
Understanding the physics of the deep solar interior, and the more exotic
environs of core-collapse supernovae (CCSN) and binary neutron-star (NS)
mergers, is of keen interest in many avenues of research. To date, this physics
is based largely on simulations via forward integration. While these
simulations provide valuable constraints, it could be insightful to adopt the
"inverse approach" as a point of comparison. Within this paradigm, parameters
of the solar interior are not output based on an assumed model, but rather are
inferred based on real data. We take the specific case of solar electron number
density, which historically is taken as output from the standard solar model.
We show how one may arrive at an independent constraint on that density profile
based on available neutrino flavor data from the Earth-based Borexino
experiment. The inference technique's ability to offer a unique lens on physics
can be extended to other datasets, and to analogous questions for CCSN and NS
mergers, albeit with simulated data.
- A plethora of long-range neutrino interactions probed by DUNE and T2HK
2404.02775 [abs] [pdf]
[abstract]
by Sanjib Kumar Agarwalla, [and 3 more]Mauricio Bustamante, Masoom Singh, and Pragyanprasu Swain [hide authors].
Upcoming neutrino experiments will soon search for new neutrino interactions
more thoroughly than ever before, boosting the prospects of extending the
Standard Model. In anticipation of this, we forecast the capability of two of
the leading long-baseline neutrino oscillation experiments, DUNE and T2HK, to
look for new flavor-dependent neutrino interactions with electrons, protons,
and neutrons that could affect the transitions between different flavors. We
interpret their sensitivity in the context of long-range neutrino interactions,
mediated by a new neutral boson lighter than $10^{-10}$ eV, and sourced by the
vast amount of nearby and distant matter in the Earth, Moon, Sun, Milky Way,
and beyond. For the first time, we explore the sensitivity of DUNE and T2HK to
a wide variety of $U(1)^\prime$ symmetries, built from combinations of lepton
and baryon numbers, each of which induces new interactions that affect
oscillations differently. We find ample sensitivity: in all cases, DUNE and
T2HK may constrain the existence of the new interaction even if it is supremely
feeble, may discover it, and, in some cases, may identify the symmetry
responsible for it.
- Constraints on the Cosmic Neutrino Background from NGC 1068
2404.02202 [abs] [pdf]
[abstract]
by Jack Franklin, [and 3 more]Ivan Martinez-Soler, Yuber F. Perez-Gonzalez, and Jessica Turner [hide authors].
We use recent evidence of TeV neutrino events from NGC 1068, detected by the
IceCube experiment, to constrain the overdensity of relic neutrinos locally and
globally. Since these high-energy neutrinos have travelled long distances
through a sea of relic neutrinos, they could have undergone scattering,
altering their observed flux on Earth. Considering only Standard Model
interactions, we constrain the relic overdensity to be $\eta\leq 3.85 \times
10^8 (5.39 \times 10^{11})$ at the 95$\%$ confidence level for overdensities
with a radius of 14 Mpc (10 kpc), assuming the sum of neutrino masses saturates
the cosmological bound, $\sum_i m_i = 0.13$ eV. We demonstrate that this limit
improves with larger neutrino masses and how it depends on the scale of the
overdensity region.
- High-energy neutrinos flavour composition as a probe of neutrino
magnetic moments
2404.02027 [abs] [pdf]
[abstract]
by Artem Popov and Alexander Studenikin.
Neutrino propagation in the Galactic and extragalactic magnetic fields is
considered. We extend an approach developed in \cite{Popov:2019nkr} to describe
neutrino flavour and spin oscillations on astrophysical baselines using wave
packets. The evolution equations for the neutrino wave packets in a uniform and
non-uniform magnetic fields are derived. The analytical expressions for
neutrino flavour and spin oscillations probabilities accounting for damping due
to the wave packet separation are obtained for the case of a uniform magnetic
field. It is shown that terms in the flavour oscillations probabilities that
depend on the magnetic field strength are characterized by two coherence
lengths. One of the coherence lengths coincides with the coherence length for
neutrino oscillations in vacuum, while the second one is proportional to the
cube of the average neutrino momentum $p_0^3$. The probabilities of flavour and
spin oscillations are calculated numerically for neutrino interacting with the
non-uniform Galactic magnetic field. It is shown that oscillations on certain
frequencies are suppressed on the Galactic scale due to the neutrino wave
packets separation. The flavour compositions of high-energy neutrino flux
coming from the Galactic centre and ultra-high energy neutrinos from an
extragalactic sourse are calculated accounting for neutrino interaction with
the magnetic field and decoherence due to the wave packet separation. It is
shown that for neutrino magnetic moments $\sim 10^{-13} \mu_B$ and larger these
flavour compositions significantly differ from ones predicted by the vacuum
neutrino oscillations scenario.}
- A Semi-blind Reconstruction of the History of Effective Number of
Neutrinos Using CMB Data
2404.01457 [abs] [pdf]
[abstract]
by Sarah Safi, [and 3 more]Marzieh Farhang, Olga Mena, and Eleonora Di Valentino [hide authors].
We explore the possibility of redshift-dependent deviations in the
contribution of relativistic degrees of freedom to the radiation budget of the
cosmos, conventionally parameterized by the effective number of neutrinos
$N_{\rm eff}$, from the predictions of the standard model. We expand the
deviations $\Delta N_{\rm eff}(z)$ in terms of top-hat functions and treat
their amplitudes as the free parameters of the theory to be measured alongside
the standard cosmological parameters by the Planck measurements of the cosmic
microwave background (CMB) anisotropies and Baryonic Acoustic Oscillations, as
well as performing forecasts for futuristic CMB surveys such as PICO and
CMB-S4. We reconstruct the history of $\Delta N_{\rm eff}$ and find that with
the current data the history is consistent with the standard scenario.
Inclusion of the new degrees of freedom in the analysis increases $H_0$ to
$68.71\pm 0.44$, slightly reducing the Hubble tension. With the smaller
forecasted errors on the $\Delta N_{\rm eff}(z)$ parametrization modes from
future CMB surveys, very accurate bounds are expected within the possible range
of dark radiation models.
March 2024
- The role of the Look Elsewhere Effect in determining the significance of
an oscillation disappearance search for a light sterile neutrino
2403.17228 [abs] [pdf]
[abstract]
by Gioacchino Ranucci.
In the ongoing vibrant experimental quest to assess whether the numerous
indications for a light sterile neutrino are only experimental fluctuations or
the manifestations of a profound and real underlying effect, one aspect which
has recently attracted a specific interest is the statistical treatment of the
data. Especially in cases of supposed positive hints, the correct statistical
assessment of their significance is of paramount importance, to avoid that
potential overstatements lead to a wrong understanding of the real status of
the experimental investigation in the field. In this work I show how latest
crucial advancements in the statistical data processing for the interpretation
of the output of a sterile search can be effectively put and understood in the
context of the Look Elsewhere Effect phenomenon, developed and now of routine
usage for results interpretation in other areas of HEP research.
- Supernovae Time Profiles as a Probe of New Physics at Neutrino
Telescopes
2403.09781 [abs] [pdf]
[abstract]
by Jeff Lazar, [and 3 more]Ying-Ying Li, Carlos A. Arguelles, and Vedran Brdar [hide authors].
Neutrino telescopes, including IceCube, can detect galactic supernova events
by observing the collective rise in photomultiplier count rates with a
sub-second time resolution. Leveraging precise timing, we demonstrate the
ability of neutrino telescopes to explore new weakly coupled states emitted
from supernovae and subsequently decaying to neutrinos. Our approach utilizes
publicly available packages, \texttt{ASTERIA} and \texttt{SNEWPY}, for
simulating detector responses and parametrizing neutrino fluxes originating
from Standard Model and new physics. We present results for two beyond the
Standard Model scenarios and introduce the tool developed for testing a diverse
range of new physics models.
- Observation of Seven Astrophysical Tau Neutrino Candidates with IceCube
2403.02516 [abs] [pdf]
[abstract]
by IceCube Collaboration, [and 404 more]R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, V. Basu, R. Bay, J. J. Beatty, J. Becker Tjus, J. Beise, C. Bellenghi, C. Benning, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, E. Blaufuss, S. Blot, F. Bontempo, J. Y. Book, C. Boscolo Meneguolo, S. Böser, O. Botner, J. Böttcher, E. Bourbeau, J. Braun, B. Brinson, J. Brostean-Kaiser, R. T. Burley, R. S. Busse, D. Butterfield, M. A. Campana, K. Carloni, E. G. Carnie-Bronca, S. Chattopadhyay, N. Chau, C. Chen, Z. Chen, D. Chirkin, S. Choi, B. A. Clark, L. Classen, A. Coleman, G. H. Collin, A. Connolly, J. M. Conrad, P. Coppin, P. Correa, D. F. Cowen, P. Dave, C. De Clercq, J. J. DeLaunay, D. Delgado, S. Deng, K. Deoskar, A. Desai, P. Desiati, K. D. de Vries, G. de Wasseige, T. DeYoung, A. Diaz, J. C. Díaz-Vélez, M. Dittmer, A. Domi, H. Dujmovic, M. A. DuVernois, T. Ehrhardt, P. Eller, E. Ellinger, S. El Mentawi, D. Elsässer, R. Engel, H. Erpenbeck, J. Evans, P. A. Evenson, K. L. Fan, K. Fang, K. Farrag, A. R. Fazely, N. Feigl, S. Fiedlschuster, A. T. Fienberg, L. Fischer, D. Fox, A. Franckowiak, A. Fritz, P. Fürst, J. Gallagher, E. Ganster, A. Garcia, L. Gerhardt, A. Ghadimi, C. Glaser, T. Glauch, T. Glüsenkamp, N. Goehlke, J. G. Gonzalez, S. Goswami, D. Grant, S. J. Gray, O. Gries, S. Griffin, S. Griswold, K. M. Groth, C. Günther, P. Gutjahr, C. Haack, A. Hallgren, R. Halliday, L. Halve, F. Halzen, H. Hamdaoui, M. Ha Minh, K. Hanson, J. Hardin, A. A. Harnisch, P. Hatch, A. Haungs, K. Helbing, J. Hellrung, F. Henningsen, L. Heuermann, N. Heyer, S. Hickford, A. Hidvegi, C. Hill, G. C. Hill, K. D. Hoffman, S. Hori, K. Hoshina, W. Hou, T. Huber, K. Hultqvist, M. Hünnefeld, R. Hussain, K. Hymon, S. In, A. Ishihara, M. Jacquart, O. Janik, M. Jansson, G. S. Japaridze, M. Jeong, M. Jin, B. J. P. Jones, D. Kang, W. Kang, X. Kang, A. Kappes, D. Kappesser, L. Kardum, T. Karg, M. Karl, A. Karle, U. Katz, M. Kauer, J. L. Kelley, A. Khatee Zathul, A. Kheirandish, J. Kiryluk, S. R. Klein, A. Kochocki, R. Koirala, H. Kolanoski, T. Kontrimas, L. Köpke, C. Kopper, D. J. Koskinen, P. Koundal, M. Kovacevich, M. Kowalski, T. Kozynets, J. Krishnamoorthi, K. Kruiswijk, E. Krupczak, A. Kumar, E. Kun, N. Kurahashi, N. Lad, C. Lagunas Gualda, M. Lamoureux, M. J. Larson, S. Latseva, F. Lauber, J. P. Lazar, J. W. Lee, K. Leonard DeHolton, A. Leszczyńska, M. Lincetto, Q. R. Liu, M. Liubarska, E. Lohfink, C. Love, C. J. Lozano Mariscal, F. Lucarelli, W. Luszczak, Y. Lyu, J. Madsen, K. B. M. Mahn, Y. Makino, E. Manao, S. Mancina, W. Marie Sainte, I. C. Mariş, S. Marka, Z. Marka, M. Marsee, I. Martinez-Soler, R. Maruyama, F. Mayhew, T. McElroy, F. McNally, J. V. Mead, K. Meagher, S. Mechbal, A. Medina, M. Meier, Y. Merckx, L. Merten, J. Micallef, J. Mitchell, T. Montaruli, R. W. Moore, Y. Morii, R. Morse, M. Moulai, T. Mukherjee, R. Naab, R. Nagai, M. Nakos, U. Naumann, J. Necker, A. Negi, M. Neumann, H. Niederhausen, M. U. Nisa, A. Noell, A. Novikov, S. C. Nowicki, A. Obertacke Pollmann, V. O'Dell, M. Oehler, B. Oeyen, A. Olivas, R. Orsoe, J. Osborn, E. O'Sullivan, H. Pandya, D. V. Pankova, N. Park, G. K. Parker, E. N. Paudel, L. Paul, C. Pérez de los Heros, J. Peterson, S. Philippen, A. Pizzuto, M. Plum, A. Pontén, Y. Popovych, M. Prado Rodriguez, B. Pries, R. Procter-Murphy, G. T. Przybylski, C. Raab, J. Rack-Helleis, K. Rawlins, Z. Rechav, A. Rehman, P. Reichherzer, G. Renzi, E. Resconi, S. Reusch, W. Rhode, B. Riedel, A. Rifaie, E. J. Roberts, S. Robertson, S. Rodan, G. Roellinghoff, M. Rongen, C. Rott, T. Ruhe, L. Ruohan, D. Ryckbosch, I. Safa, J. Saffer, D. Salazar-Gallegos, P. Sampathkumar, S. E. Sanchez Herrera, A. Sandrock, M. Santander, S. Sarkar, S. Sarkar, J. Savelberg, P. Savina, M. Schaufel, H. Schieler, S. Schindler, L. Schlickmann, B. Schlüter, F. Schlüter, N. Schmeisser, T. Schmidt, J. Schneider, F. G. Schröder, L. Schumacher, G. Schwefer, S. Sclafani, D. Seckel, M. Seikh, S. Seunarine, R. Shah, A. Sharma, S. Shefali, N. Shimizu, M. Silva, B. Skrzypek, B. Smithers, R. Snihur, J. Soedingrekso, A. Søgaard, D. Soldin, P. Soldin, G. Sommani, C. Spannfellner, G. M. Spiczak, M. Stamatikos, T. Stanev, T. Stezelberger, T. Stürwald, T. Stuttard, G. W. Sullivan, I. Taboada, S. Ter-Antonyan, M. Thiesmeyer, W. G. Thompson, J. Thwaites, S. Tilav, K. Tollefson, C. Tönnis, S. Toscano, D. Tosi, A. Trettin, C. F. Tung, R. Turcotte, J. P. Twagirayezu, B. Ty, M. A. Unland Elorrieta, A. K. Upadhyay, K. Upshaw, N. Valtonen-Mattila, J. Vandenbroucke, N. van Eijndhoven, D. Vannerom, J. van Santen, J. Vara, J. Veitch-Michaelis, M. Venugopal, M. Vereecken, S. Verpoest, D. Veske, A. Vijai, C. Walck, C. Weaver, P. Weigel, A. Weindl, J. Weldert, A. Y. Wen, C. Wendt, J. Werthebach, M. Weyrauch, N. Whitehorn, C. H. Wiebusch, N. Willey, D. R. Williams, L. Witthaus, A. Wolf, M. Wolf, G. Wrede, X. W. Xu, J. P. Yanez, E. Yildizci, S. Yoshida, R. Young, F. Yu, S. Yu, Z. Zhang, P. Zhelnin, P. Zilberman, and M. Zimmerman [hide authors].
We report on a measurement of astrophysical tau neutrinos with 9.7 years of
IceCube data. Using convolutional neural networks trained on images derived
from simulated events, seven candidate $\nu_\tau$ events were found with
visible energies ranging from roughly 20 TeV to 1 PeV and a median expected
parent $\nu_\tau$ energy of about 200 TeV. Considering backgrounds from
astrophysical and atmospheric neutrinos, and muons from $\pi^\pm/K^\pm$ decays
in atmospheric air showers, we obtain a total estimated background of about 0.5
events, dominated by non-$\nu_\tau$ astrophysical neutrinos. Thus, we rule out
the absence of astrophysical $\nu_\tau$ at the $5\sigma$ level. The measured
astrophysical $\nu_\tau$ flux is consistent with expectations based on
previously published IceCube astrophysical neutrino flux measurements and
neutrino oscillations.
- A new Wolfenstein-like expansion of lepton flavor mixing towards
understanding its fine structure
2403.00559 [abs] [pdf]
[abstract]
by Zhi-zhong Xing.
Taking the tri-bimaximal flavor mixing pattern as a particular basis, we
propose a new way to expand the $3\times 3$ unitary
Pontecorvo-Maki-Nakagawa-Sakata (PMNS) lepton flavor mixing matrix $U$ in
powers of the magnitude of its smallest element $\xi \equiv \left|U^{}_{e
3}\right| \simeq 0.149$. Such a Wolfenstein-like parametrization of $U$ allows
us to easily describe the salient features and fine structures of flavor mixing
and CP violation, both in vacuum and in matter.
February 2024
- Prospects for measuring time variation of astrophysical neutrino sources
at dark matter detectors
2402.18454 [abs] [pdf]
[abstract]
by Yi Zhuang, [and 3 more]Louis E. Strigari, Lei Jin, and Samiran Sinha [hide authors].
We study the prospects for measuring the time variation of solar and
atmospheric neutrino fluxes at future large-scale Xenon and Argon dark matter
detectors. For solar neutrinos, a yearly time variation arises from the
eccentricity of the Earth's orbit, and, for charged current interactions, from
a smaller energy-dependent day-night variation to due flavor regeneration as
neutrinos travel through the Earth. For a 100-ton Xenon detector running for 10
years with a Xenon-136 fraction of $\lesssim 0.1\%$, in the electron recoil
channel a time-variation amplitude of about 0.8\% is detectable with a power of
90\% and the level of significance of 10\%. This is sufficient to detect time
variation due to eccentricity, which has amplitude of $\sim 3\%$. In the
nuclear recoil channel, the detectable amplitude is about 10\% under current
detector resolution and efficiency conditions, and this generally reduces to
about 1\% for improved detector resolution and efficiency, the latter of which
is sufficient to detect time variation due to eccentricity. Our analysis
assumes both known and unknown periods. We provide scalings to determine the
sensitivity to an arbitrary time-varying amplitude as a function of detector
parameters. Identifying the time variation of the neutrino fluxes will be
important for distinguishing neutrinos from dark matter signals and other
detector-related backgrounds, and extracting properties of neutrinos that can
be uniquely studied in dark matter experiments.
- Characterization of the Astrophysical Diffuse Neutrino Flux using
Starting Track Events in IceCube
2402.18026 [abs] [pdf]
[abstract]
by R. Abbasi, [and 418 more]M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, L. Ausborm, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, S. Bash, V. Basu, R. Bay, J. J. Beatty, J. Becker Tjus, J. Beise, C. Bellenghi, C. Benning, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, E. Blaufuss, S. Blot, F. Bontempo, J. Y. Book, C. Boscolo Meneguolo, S. Böser, O. Botner, J. Böttcher, J. Braun, B. Brinson, J. Brostean-Kaiser, L. Brusa, R. T. Burley, R. S. Busse, D. Butterfield, M. A. Campana, I. Caracas, K. Carloni, J. Carpio, S. Chattopadhyay, N. Chau, Z. Chen, D. Chirkin, S. Choi, B. A. Clark, A. Coleman, G. H. Collin, A. Connolly, J. M. Conrad, P. Coppin, R. Corley, P. Correa, D. F. Cowen, P. Dave, C. De Clercq, J. J. DeLaunay, D. Delgado, S. Deng, K. Deoskar, A. Desai, P. Desiati, K. D. de Vries, G. de Wasseige, T. DeYoung, A. Diaz, J. C. Díaz-Vélez, M. Dittmer, A. Domi, L. Draper, H. Dujmovic, K. Dutta, M. A. DuVernois, T. Ehrhardt, L. Eidenschink, A. Eimer, P. Eller, E. Ellinger, S. El Mentawi, D. Elsässer, R. Engel, H. Erpenbeck, J. Evans, P. A. Evenson, K. L. Fan, K. Fang, K. Farrag, A. R. Fazely, A. Fedynitch, N. Feigl, S. Fiedlschuster, C. Finley, L. Fischer, D. Fox, A. Franckowiak, P. Fürst, J. Gallagher, E. Ganster, A. Garcia, E. Genton, L. Gerhardt, A. Ghadimi, C. Girard-Carillo, C. Glaser, T. Glüsenkamp, J. G. Gonzalez, S. Goswami, A. Granados, D. Grant, S. J. Gray, O. Gries, S. Griffin, S. Griswold, K. M. Groth, C. Günther, P. Gutjahr, C. Ha, C. Haack, A. Hallgren, R. Halliday, L. Halve, F. Halzen, H. Hamdaoui, M. Ha Minh, M. Handt, K. Hanson, J. Hardin, A. A. Harnisch, P. Hatch, A. Haungs, J. Häußler, K. Helbing, J. Hellrung, J. Hermannsgabner, L. Heuermann, N. Heyer, S. Hickford, A. Hidvegi, C. Hill, G. C. Hill, K. D. Hoffman, S. Hori, K. Hoshina, M. Hostert, W. Hou, T. Huber, K. Hultqvist, M. Hünnefeld, R. Hussain, K. Hymon, A. Ishihara, W. Iwakiri, M. Jacquart, O. Janik, M. Jansson, G. S. Japaridze, M. Jeong, M. Jin, B. J. P. Jones, N. Kamp, D. Kang, W. Kang, X. Kang, A. Kappes, D. Kappesser, L. Kardum, T. Karg, M. Karl, A. Karle, A. Katil, U. Katz, M. Kauer, J. L. Kelley, M. Khanal, A. Khatee Zathul, A. Kheirandish, J. Kiryluk, S. R. Klein, A. Kochocki, R. Koirala, H. Kolanoski, T. Kontrimas, L. Köpke, C. Kopper, D. J. Koskinen, P. Koundal, M. Kovacevich, M. Kowalski, T. Kozynets, J. Krishnamoorthi, K. Kruiswijk, E. Krupczak, A. Kumar, E. Kun, N. Kurahashi, N. Lad, C. Lagunas Gualda, M. Lamoureux, M. J. Larson, S. Latseva, F. Lauber, J. P. Lazar, J. W. Lee, K. Leonard DeHolton, A. Leszczyńska, J. Liao, M. Lincetto, M. Liubarska, E. Lohfink, C. Love, C. J. Lozano Mariscal, L. Lu, F. Lucarelli, W. Luszczak, Y. Lyu, J. Madsen, E. Magnus, K. B. M. Mahn, Y. Makino, E. Manao, S. Mancina, W. Marie Sainte, I. C. Mariş, S. Marka, Z. Marka, M. Marsee, I. Martinez-Soler, R. Maruyama, F. Mayhew, T. McElroy, F. McNally, J. V. Mead, K. Meagher, S. Mechbal, A. Medina, M. Meier, Y. Merckx, L. Merten, J. Micallef, J. Mitchell, T. Montaruli, R. W. Moore, Y. Morii, R. Morse, M. Moulai, T. Mukherjee, R. Naab, R. Nagai, M. Nakos, U. Naumann, J. Necker, A. Negi, M. Neumann, H. Niederhausen, M. U. Nisa, A. Noell, A. Novikov, S. C. Nowicki, A. Obertacke Pollmann, V. O'Dell, B. Oeyen, A. Olivas, R. Orsoe, J. Osborn, E. O'Sullivan, H. Pandya, N. Park, G. K. Parker, E. N. Paudel, L. Paul, C. Pérez de los Heros, T. Pernice, J. Peterson, S. Philippen, A. Pizzuto, M. Plum, A. Pontén, Y. Popovych, M. Prado Rodriguez, B. Pries, R. Procter-Murphy, G. T. Przybylski, C. Raab, J. Rack-Helleis, K. Rawlins, Z. Rechav, A. Rehman, P. Reichherzer, E. Resconi, S. Reusch, W. Rhode, B. Riedel, A. Rifaie, E. J. Roberts, S. Robertson, S. Rodan, G. Roellinghoff, M. Rongen, A. Rosted, C. Rott, T. Ruhe, L. Ruohan, D. Ryckbosch, I. Safa, J. Saffer, D. Salazar-Gallegos, P. Sampathkumar, A. Sandrock, M. Santander, S. Sarkar, S. Sarkar, J. Savelberg, P. Savina, P. Schaile, M. Schaufel, H. Schieler, S. Schindler, B. Schlüter, F. Schlüter, N. Schmeisser, T. Schmidt, J. Schneider, F. G. Schröder, L. Schumacher, S. Sclafani, D. Seckel, M. Seikh, M. Seo, S. Seunarine, P. Sevle Myhr, R. Shah, S. Shefali, N. Shimizu, M. Silva, B. Skrzypek, B. Smithers, R. Snihur, J. Soedingrekso, A. Søgaard, D. Soldin, P. Soldin, G. Sommani, C. Spannfellner, G. M. Spiczak, C. Spiering, M. Stamatikos, T. Stanev, T. Stezelberger, T. Stürwald, T. Stuttard, G. W. Sullivan, I. Taboada, S. Ter-Antonyan, A. Terliuk, M. Thiesmeyer, W. G. Thompson, J. Thwaites, S. Tilav, K. Tollefson, C. Tönnis, S. Toscano, D. Tosi, A. Trettin, R. Turcotte, J. P. Twagirayezu, M. A. Unland Elorrieta, A. K. Upadhyay, K. Upshaw, A. Vaidyanathan, N. Valtonen-Mattila, J. Vandenbroucke, N. van Eijndhoven, D. Vannerom, J. van Santen, J. Vara, J. Veitch-Michaelis, M. Venugopal, M. Vereecken, S. Verpoest, D. Veske, A. Vijai, C. Walck, A. Wang, C. Weaver, P. Weigel, A. Weindl, J. Weldert, A. Y. Wen, C. Wendt, J. Werthebach, M. Weyrauch, N. Whitehorn, C. H. Wiebusch, D. R. Williams, L. Witthaus, A. Wolf, M. Wolf, G. Wrede, X. W. Xu, J. P. Yanez, E. Yildizci, S. Yoshida, R. Young, S. Yu, T. Yuan, Z. Zhang, P. Zhelnin, P. Zilberman, and M. Zimmerman [hide authors].
A measurement of the diffuse astrophysical neutrino spectrum is presented
using IceCube data collected from 2011-2022 (10.3 years). We developed novel
detection techniques to search for events with a contained vertex and exiting
track induced by muon neutrinos undergoing a charged-current interaction.
Searching for these starting track events allows us to not only more
effectively reject atmospheric muons but also atmospheric neutrino backgrounds
in the southern sky, opening a new window to the sub-100 TeV astrophysical
neutrino sky. The event selection is constructed using a dynamic starting track
veto and machine learning algorithms. We use this data to measure the
astrophysical diffuse flux as a single power law flux (SPL) with a best-fit
spectral index of $\gamma = 2.58 ^{+0.10}_{-0.09}$ and per-flavor normalization
of $\phi^{\mathrm{Astro}}_{\mathrm{per-flavor}} = 1.68 ^{+0.19}_{-0.22} \times
10^{-18} \times \mathrm{GeV}^{-1} \mathrm{cm}^{-2} \mathrm{s}^{-1}
\mathrm{sr}^{-1}$ (at 100 TeV). The sensitive energy range for this dataset is
3 - 550 TeV under the SPL assumption. This data was also used to measure the
flux under a broken power law, however we did not find any evidence of a low
energy cutoff.
- Quantum Decoherence effects on precision measurements at DUNE and T2HK
2402.16395 [abs] [pdf]
[abstract]
by G. Barenboim, [and 3 more]A. Calatayud-Cadenillas, A. M. Gago, and C. A. Ternes [hide authors].
We investigate the potential impact of neutrino quantum decoherence on the
precision measurements of standard neutrino oscillation parameters in the DUNE
and T2HK experiments. We show that the measurement of $\delta_\text{CP}$,
$\sin^2\theta_{13}$ and $\sin^2\theta_{23}$ is stronger effected in DUNE than
in T2HK. On the other hand, DUNE would have a better sensitivity than T2HK to
observe decoherence effects. By performing a combined analysis of DUNE and T2HK
we show that a robust measurement of standard parameters would be possible,
which is not guaranteed with DUNE data alone.
- Constraints on new physics with (anti)neutrino-nucleon scattering data
2402.14115 [abs] [pdf]
[abstract]
by Oleksandr Tomalak, [and 4 more]Minerba Betancourt, Kaushik Borah, Richard J. Hill, and Thomas Junk [hide authors].
New physics contributions to the (anti)neutrino-nucleon elastic scattering
process can be constrained by precision measurements, with controlled Standard
Model uncertainties. In a large class of new physics models, interactions
involving charged leptons of different flavor can be related, and the large
muon flavor component of accelerator neutrino beams can mitigate the lepton
mass suppression that occurs in other low-energy measurements. We employ the
recent high-statistics measurement of the cross section for $\bar{\nu}_\mu p
\to \mu^+ n$ scattering on the hydrogen atom by MINERvA to place new confidence
intervals on tensor and scalar neutrino-nucleon interactions: $\mathfrak{Re}
C_T = -1^{+14}_{-13} \times 10^{-4}$, $|\mathfrak{Im} C_T| \le 1.3 \times
10^{-3}$, and $|\mathfrak{Im} C_S| = 45^{+13}_{-19} \times 10^{-3}$. These
results represent a reduction in uncertainty by a factor of $2.1$, $3.1$, and
$1.2$, respectively, compared to existing constraints from precision beta
decay.
- Neutrino Rate Predictions for FASER
2402.13318 [abs] [pdf]
[abstract]
by FASER Collaboration, [and 99 more]Roshan Mammen Abraham, John Anders, Claire Antel, Akitaka Ariga, Tomoko Ariga, Jeremy Atkinson, Florian U. Bernlochner, Tobias Boeckh, Jamie Boyd, Lydia Brenner, Angela Burger, Franck Cadoux, Roberto Cardella, David W. Casper, Charlotte Cavanagh, Xin Chen, Andrea Coccaro, Stephane Débieux, Monica D'Onofrio, Ansh Desai, Sergey Dmitrievsky, Sinead Eley, Yannick Favre, Deion Fellers, Jonathan L. Feng, Carlo Alberto Fenoglio, Didier Ferrere, Max Fieg, Wissal Filali, Stephen Gibson, Sergio Gonzalez-Sevilla, Yuri Gornushkin, Carl Gwilliam, Daiki Hayakawa, Shih-Chieh Hsu, Zhen Hu, Giuseppe Iacobucci, Tomohiro Inada, Luca Iodice, Sune Jakobsen, Hans Joos, Enrique Kajomovitz, Hiroaki Kawahara, Alex Keyken, Felix Kling, Daniela Köck, Pantelis Kontaxakis, Umut Kose, Rafaella Kotitsa, Susanne Kuehn, Thanushan Kugathasan, Helena Lefebvre, Lorne Levinson, Ke Li, Jinfeng Liu, Margaret S. Lutz, Jack MacDonald, Chiara Magliocca, Fulvio Martinelli, Lawson McCoy, Josh McFayden, Andrea Pizarro Medina, Matteo Milanesio, Théo Moretti, Magdalena Munker, Mitsuhiro Nakamura, Toshiyuki Nakano, Friedemann Neuhaus, Laurie Nevay, Ken Ohashi, Hidetoshi Otono, Hao Pang, Lorenzo Paolozzi, Brian Petersen, Markus Prim, Michaela Queitsch-Maitland, Hiroki Rokujo, Elisa Ruiz-Choliz, André Rubbia, Jorge Sabater-Iglesias, Osamu Sato, Paola Scampoli, Kristof Schmieden, Matthias Schott, Anna Sfyrla, Mansoora Shamim, Savannah Shively, Yosuke Takubo, Noshin Tarannum, Ondrej Theiner, Eric Torrence, Svetlana Vasina, Benedikt Vormwald, Di Wang, Yuxiao Wang, Eli Welch, Samuel Zahorec, Stefano Zambito, and Shunliang Zhang [hide authors].
The Forward Search Experiment (FASER) at CERN's Large Hadron Collider (LHC)
has recently directly detected the first collider neutrinos. Neutrinos play an
important role in all FASER analyses, either as signal or background, and it is
therefore essential to understand the neutrino event rates. In this study, we
update previous simulations and present prescriptions for theoretical
predictions of neutrino fluxes and cross sections, together with their
associated uncertainties. With these results, we discuss the potential for
possible measurements that could be carried out in the coming years with the
FASER neutrino data to be collected in LHC Run 3 and Run 4.
- Boosting Neutrino Mass Ordering Sensitivity with Inelasticity for
Atmospheric Neutrino Oscillation Measurement
2402.13308 [abs] [pdf]
[abstract]
by Santiago Giner Olavarrieta, [and 4 more]Miaochen Jin, Carlos A. Argüelles, Pablo Fernández, and Ivan Martínez-Soler [hide authors].
In this letter, we study the potential of boosting the atmospheric neutrino
experiments sensitivity to the neutrino mass ordering (NMO) sensitivity by
incorporating inelasticity measurements. We show how this observable improves
the sensitivity to the NMO and the precision of other neutrino oscillation
parameters relevant to atmospheric neutrinos, specifically in the
IceCube-Upgrade and KM3NeT-ORCA detectors. Our results indicate that an
oscillation analysis of atmospheric neutrinos including inelasticity
information has the potential to enhance the ordering discrimination by several
units of $\chi^2$ in the assumed scenario of 5 and 3 years of running of
IceCube-Upgrade and KM3NeT-ORCA detectors, respectively.
- Synergy between DUNE and T2HKK to probe Invisible Neutrino Decay
2402.13235 [abs] [pdf]
[abstract]
by Zannatun Firdowzy Dey and Debajyoti Dutta.
We address the consequence of invisible neutrino decay within the framework
of two long base-line neutrino experiments: T2HKK
(Tokai-to-Hyper-Kamiokande-to-Korea) and DUNE (Deep Underground Neutrino
experiment). Our primary objective is to bring out the aspects of CC (charged
current) and NC (neutral current) measurements at DUNE in the context of
invisible neutrino decay. We find that the inclusion of NC measurements with
the CC measurements enhances its ability to constrain invisible neutrino decay.
Further, the synergy between DUNE and T2HKK improves the constraints on
invisible neutrino decay. At 3$\sigma$ C.L. (confidence level) the derived
constraint is $\tau_{3}/m_{3}\geq6.21\times10^{-11}$ s/eV. Additionally, if
nature prefers $\nu_{3}$ to be unstable and the decay width is $\tau_{3}/m_{3}=
2.2\times10^{-11}$ s/eV, this combination can exclude the no-decay scenario at
more than 5$\sigma$ C.L. Although the CP sensitivity is not much hindered in
the presence of invisible neutrino decay, the measurements of $\theta_{23}$ and
the ability to resolve octant of $\theta_{23}$ is significantly influenced in
these individual experiments. In the presence of invisible neutrino decay, the
synergy between DUNE and T2HKK can exclude the wrong octant somewhat more
effectively than either experiment alone.
- Constraining neutrino-DM interactions with Milky Way dwarf spheroidals
and supernova neutrinos
2402.08718 [abs] [pdf]
[abstract]
by Sean Heston, Shunsaku Horiuchi, and Satoshi Shirai.
We constrain the neutrino-dark matter cross section using properties of the
dark matter density profiles of Milky Way dwarf spheroidal galaxies. The
constraint arises from core-collapse supernova neutrinos scattering on dark
matter as a form of energy injection, allowing the transformation of the dark
matter density profile from a cusped profile to a flatter profile. We assume a
standard cosmology of dark energy and cold, collisionless, and
non-self-interacting dark matter. By requiring that the dark matter cores do
not lose too much mass or overshoot constraints from stellar kinematics, we
place an upper limit on the cross section of $\sigma_{\nu-\mathrm{DM}}(E_\nu=15
\, \mathrm{MeV}, m_\chi\lesssim130 \, \mathrm{GeV}) \approx 3.4 \times 10^{-23}
\, \mathrm{cm^2}$ and $\sigma_{\nu-\mathrm{DM}}(E_\nu=15 \, \mathrm{MeV},
m_\chi\gtrsim130 \, \mathrm{GeV}) \approx 3.2 \times 10^{-27} \left(
\frac{m_\chi}{1\,\mathrm{GeV}}\right)^2\, \mathrm{cm^2}$, which is stronger
than previous bounds for these energies. Consideration of baryonic feedback or
host galaxy effects on the dark matter profile can strengthen this constraint.
- Characterization and Optimization of a Cryogenic Pure CsI Detector with
Remarkable Light Yield and Unprecedented Energy Resolution for CLOVERS
Experiment
2402.05026 [abs] [pdf]
[abstract]
by Chenguang Su, [and 6 more]Qian Lin, Linqquan Kong, Shi Chen, Kimiya Moharrami, Yangheng Zheng, and Jin Li [hide authors].
In this study, we conducted a comprehensive characterization and optimization
of a cryogenic pure CsI (pCsI) detector. We utilized a \SI{2}{\centi\metre}
cubic crystal coupled with a HAMAMATSU R11065 photomultiplier tube (PMT),
achieving a remarkable light yield of \SI{35.2}{PE/\keV_{ee}} and an
unprecedented energy resolution of \SI{6.9}{\%} at \SI{60}{\keV}. Additionally,
we measured the scintillation decay time of pCsI, which proved to be
significantly faster than that of CsI(Na) at room temperature. Furthermore, we
investigated the impact of temperature, surface treatment, and crystal shape on
the light yield. Notably, the light yield peaked at approximately \SI{20}{\K}
and remained stable within the range of \SI{70}-\SI{100}{\K}. We observed that
the light yield of polished crystals was approximately 1.5 times greater than
that of ground crystals, while the crystal shape exhibited minimal influence on
the light yield. These results are crucial for the design of the \SI{10}{\kg}
pCsI detector for the future CLOVERS (Coherent eLastic neutrinO(V)-nucleus
scattERing at China Spallation Neutron Source (CSNS)) experiment.
- Quantum Decoherence Effects: a complete treatment
2402.03438 [abs] [pdf]
[abstract]
by Gabriela Barenboim and Alberto M. Gago.
Physical systems in real life are inextricably linked to their surroundings
and never completely separated from them. Truly closed systems do not exist.
The phenomenon of decoherence, which is brought about by the interaction with
the environment, removes the relative phase of quantum states in superposition
and makes them incoherent. In neutrino physics, decoherence, although
extensively studied has only been analyzed thus far, exclusively in terms of
its dissipative characteristics. While it is true that dissipation, or the
exponential suppression, eventually is the main observable effect, the exchange
of energy between the medium and the system, is an important factor that has
been overlooked up until now. In this work, we introduce this term and analyze
its consequences.
- Probing the Sterile Neutrino Dipole Portal with SN1987A and Low-Energy
Supernovae
2402.01624 [abs] [pdf]
[abstract]
by Garv Chauhan, [and 3 more]Shunsaku Horiuchi, Patrick Huber, and Ian M. Shoemaker [hide authors].
BSM electromagnetic properties of neutrinos may lead to copious production of
sterile neutrinos in the hot and dense core of a core-collapse supernova. In
this work, we focus on the active-sterile transition magnetic moment portal for
heavy sterile neutrinos. Firstly, we revisit the SN1987A cooling bounds for
dipole portal using the integrated luminosity method, which yields more
reliable results (especially in the trapping regime) compared to the previously
explored via emissivity loss, aka the Raffelt criterion. Secondly, we obtain
strong bounds on the dipole coupling strength reaching as low as $10^{-11}
\text{ GeV}^{-1}$ from energy deposition, i.e., constrained from the
observation of explosion energies of underluminous Type IIP supernovae. In
addition, we find that sterile neutrino production from Primakoff upscattering
off of proton dominates over scattering off of electron for low sterile
neutrino masses.
- Upper Limits on the Cosmic Neutrino Background from Cosmic Rays
2402.00985 [abs] [pdf]
[abstract]
by Mar Císcar-Monsalvatje, Gonzalo Herrera, and Ian M. Shoemaker.
Extragalactic and galactic cosmic rays scatter with the cosmic neutrino
background during propagation to Earth, yielding a flux of relic neutrinos
boosted to larger energies. If an overdensity of relic neutrinos is present in
galaxies, and neutrinos are massive enough, this flux might be detectable by
high-energy neutrino experiments. For a lightest neutrino of mass $m_{\nu} \sim
0.1$ eV, we find an upper limit on the local relic neutrino overdensity of
$\sim 10^{13}$ and an upper limit on the relic neutrino overdensity at TXS
0506+056 of $\sim 10^{10}$. Future experiments like GRAND or IceCube-Gen2 could
improve these bounds by orders of magnitude.
- Testing the Number of Neutrino Species with a Global Fit of Neutrino
Data
2402.00490 [abs] [pdf]
[abstract]
by Manuel Ettengruber, Alan Zander, and Philipp Eller.
We present the first experimental constraints on models with many additional
neutrino species in an analysis of current neutrino data. These types of models
are motivated as a solution to the hierarchy problem by lowering the species
scale of gravity to TeV. Additionally, they offer a natural mechanism to
generate small neutrino masses and provide interesting dark matter candidates.
This study analyzes data from DayaBay, KamLAND, MINOS, NOvA and KATRIN. We do
not find evidence for the presence of any additional neutrino species,
therefore we report lower bounds on the allowed number of neutrino species
realized in nature. For the normal/inverted neutrino mass ordering, we can give
a lower bound on the number of neutrino species of O(30) and O(100),
respectively, over a large range of the parameter space.
January 2024
- The Sun and core-collapse supernovae are leading probes of the neutrino
lifetime
2402.00116 [abs] [pdf]
[abstract]
by Pablo Martínez-Miravé, Irene Tamborra, and Mariam Tórtola.
The large distances travelled by neutrinos emitted from the Sun and
core-collapse supernovae together with the characteristic energy of such
neutrinos provide ideal conditions to probe their lifetime, when the decay
products evade detection. We investigate the prospects of probing invisible
neutrino decay capitalising on the detection of solar and supernova neutrinos
as well as the diffuse supernova neutrino background (DSNB) in the
next-generation neutrino observatories Hyper-Kamiokande, DUNE, JUNO, DARWIN,
and RES-NOVA. We find that future solar neutrino data will be sensitive to
values of the lifetime-to-mass ratio $\tau_1/m_1$ and $\tau_2/m_2$ of
$\mathcal{O}(10^{-1} - 10^{-2})$ s/eV. From a core-collapse supernova explosion
at $10$ kpc, lifetime-to-mass ratios of the three mass eigenstates of
$\mathcal{O}(10^5)$ s/eV could be tested. After $20$ years of data taking, the
DSNB would extend the sensitivity reach of $\tau_1/m_1$ to $10^{8}$ s/eV. These
results promise an improvement of about $6 -15$ orders of magnitude on the
values of the decay parameters with respect to existing limits.
- Leptonic neutral-current probes in a short-distance DUNE-like setup
2402.00114 [abs] [pdf]
[abstract]
by Salvador Centelles Chuliá, O. G. Miranda, and Jose W. F. Valle.
Precision measurements of neutrino-electron scattering may provide a viable
way to test the non-minimal form of the charged and neutral current weak
interactions within a hypothetical near-detector setup for the Deep Underground
Neutrino Experiment (DUNE). Although low-statistics, these processes are clean
and provide information complementing the results derived from oscillation
studies. They could shed light on the scale of neutrino mass generation in
low-scale seesaw schemes.
- Invisible neutrino decay at long-baseline neutrino oscillation
experiments
2401.14316 [abs] [pdf]
[abstract]
by Christoph A. Ternes and Giulia Pagliaroli.
We perform an updated analysis of long-baseline accelerator data in the
framework of neutrino oscillations in presence of invisible neutrino decay. We
analyze data from T2K, NOvA and MINOS/MINOS+ and show that the combined
analysis of all experiments improves the previous bound from long-baseline data
by approximately one order of magnitude.
- $νe\toνe$ scattering with massive Dirac or Majorana neutrinos and
general interactions
2401.14305 [abs] [pdf]
[abstract]
by Juan Manuel Márquez, Pablo Roig, and Mónica Salinas.
We calculate the neutrino-electron elastic scattering cross section,
extending the results previously obtained in arXiv:1702.05721v2, in the
presence of generic new interactions that take into account all the effects
caused by finite neutrino masses. We address the potential significance of a
heavy neutrino sector during precision measurements, particularly for tau
neutrinos scattering with masses in the MeV range, for which the existing upper
bounds on $|U_{\tau 4}|^2$ would result in conceivably measurable
contributions. Finally, we comment on the possibility to distinguish between
Dirac and Majorana neutrinos, including the analysis of the new emerging
parameters and its application to illustrative model-dependent scenarios.
- νOscillation: a software package for computation and simulation of
neutrino propagation and interaction
2401.13215 [abs] [pdf]
[abstract]
by Seonghyeok Jang, [and 4 more]Eunju Jeon, Eunil Won, Young Ju Ko, and Kyungmin Lee [hide authors].
The behavior of neutrinos is the only phenomenon that cannot be explained by
the standard model of particle physics. Because of these mysterious neutrino
interactions observed in nature, at present, there is growing interest in this
field and ongoing or planned neutrino experiments are seeking solutions to this
mystery very actively. The design of neutrino experiments and the analysis of
neutrino data rely on precise computations of neutrino oscillations and
scattering processes in general. Motivated by this, we developed a software
package that calculates neutrino production and oscillation in nuclear
reactors, neutrino-electron scattering of solar neutrinos, and the oscillation
of neutrinos from radioactive isotopes for the search of sterile neutrinos.
This software package is validated by reproducing the result of calculations
and observations in other publications. We also demonstrate the feasibility of
this package by calculating the sensitivity of a liquid scintillator detector,
currently in planning, to the sterile neutrinos. This work is expected to be
used in designs of future neutrino experiments.
- Jovian Signal at BOREXINO
2401.13043 [abs] [pdf]
[abstract]
by Saeed Ansarifard and Yasaman Farzan.
The BOREXINO experiment has been collecting solar neutrino data since 2007,
providing the opportunity to study the variation of the event rate over a
decade. We find that at 96 \% C.L., the rate of low energy events shows a time
modulation favoring a correlation with a flux from Jupiter. We present a new
physics model, the Jovian Whisper Model, based on dark matter of mass $\sim
0.1-4$ GeV captured by Jupiter that can account for such modulation. We discuss
how the Jovian Whisper Model (JWM) can be tested.
- Light vector bosons and the weak mixing angle in the light of future
germanium-based reactor CE$ν$NS experiments
2401.13025 [abs] [pdf]
[abstract]
by Manfred Lindner, Thomas Rink, and Manibrata Sen.
In this work, the sensitivity of future germanium-based reactor neutrino
experiments to the weak mixing angle $\sin^{2}\theta_{W}$, and to the presence
of new light vector bosons is investigated. By taking into account key
experimental features with their uncertainties and the application of a
data-driven and state-of-the-art reactor antineutrino spectrum, the impact of
detection threshold and experimental exposure is assessed in detail for an
experiment relying on germanium semiconductor detectors. With the established
analysis framework, the precision on the Weinberg angle, and capability of
probing the parameter space of a universally coupled mediator model, as well as
a U(1)$_{\rm B-L}$-symmetric model are quantified. Our investigation finds the
next-generation of germanium-based reactor neutrino experiments in good shape
to determine the Weinberg angle $\sin^{2}\theta_{W}$ with $<10$ % precision
using the low-energetic neutrino channel of CE$\nu$NS. In addition, the current
limits on new light vector bosons determined by reactor experiments can be
lowered by about an order of magnitude via the combination of both CE$\nu$NS
and E$\nu$eS. Consequently, our findings provide strong phenomenological
support for future experimental endeavours close to a reactor site.
- A non-unitary solar constraint for long-baseline neutrino experiments
2401.12829 [abs] [pdf]
[abstract]
by Andres Lopez Moreno.
Long-baseline neutrino oscillation experiments require external constraints
on $\sin^2\theta_{12}$ and $\Delta m_{21}^2$ to make precision measurements of
the leptonic mixing matrix. These constraints come from measurements of the
Mikheyev-Smirnov-Wolfenstein (MSW) mixing in solar neutrinos. Here we develop
an MSW large mixing angle approximation in the presence of heavy neutral
leptons which adds a single new parameter ($\alpha_{11}$) representing the
magnitude of the mixing between the $\nu_e$ state and the heavy sector. We use
data from the Borexino, SNO and KamLAND collaborations to find a solar
constraint appropriate for heavy neutral lepton searches in long-baseline
oscillation experiments. Solar data limits the magnitude of the non-unitary
parameter to $(1-\alpha_{11}) < 0.046$ at the $99\%$ credible interval and
yields a strongly correlated constraint on the solar mass splitting and the
magnitude of $\nu_e$ non-unitary mixing.
- The Smallness of Matter Effects in Long-Baseline Muon Neutrino
Disappearance
2401.10326 [abs] [pdf]
[abstract]
by Peter B. Denton and Stephen J. Parke.
Current long-baseline accelerator experiments, NOvA and T2K, are making
excellent measurements of neutrino oscillations and the next generation of
experiments, DUNE and HK, will make measurements at the $\mathcal O(1\%)$ level
of precision. These measurements are a combination of the appearance channel
which is more challenging experimentally but depends on many oscillation
parameters, and the disappearance channel which is somewhat easier and allows
for precision measurements of the atmospheric mass splitting and the
atmospheric mixing angle. It is widely recognized that the matter effect plays
a key role in the appearance probability, yet the effect on the disappearance
probability is surprisingly small for these experiments. Here we investigate
both exactly how small the effect is and show that it just begins to become
relevant in the high statistics regime of DUNE.
- Final CONUS results on coherent elastic neutrino nucleus scattering at
the Brokdorf reactor
2401.07684 [abs] [pdf]
[abstract]
by N. Ackermann, [and 15 more]H. Bonet, A. Bonhomme, C. Buck, K. Fülber, J. Hakenmüller, J. Hempfling, J. Henrichs, G. Heusser, M. Lindner, W. Maneschg, T. Rink, E. Sanchez Garcia, J. Stauber, H. Strecker, and R. Wink [hide authors].
The CONUS experiment studies coherent elastic neutrino nucleus scattering in
four 1 kg germanium spectrometers. Low ionization energy thresholds of 210 eV
were achieved. The detectors were operated inside an optimized shield at the
Brokdorf nuclear power plant which provided a reactor antineutrino flux of up
to $2.3\cdot10^{13}$ cm$^{-2}$s$^{-1}$. In the final phase of data collection
at this site, the constraints on the neutrino interaction rate were improved by
an order of magnitude as compared to the previous CONUS analysis. The new limit
of less than 0.34 signal events kg$^{-1}$d$^{-1}$ is within a factor 2 of the
rate predicted by the Standard Model.
- Neutrino-antineutrino Asymmetry of C$ν$B on the Surface of the Round
Earth
2401.07347 [abs] [pdf]
[abstract]
by Guo-yuan Huang.
It has been claimed that the coherent scattering of relic neutrinos with the
Earth will result in a neutrino-antineutrino asymmetry of
$\mathcal{O}(10^{-4})$ on the Earth surface, which is five orders of magnitude
larger than the naive model expectation. In this work we show that this
overdensity was overestimated for the perfectly round Earth by solving the
exact solution with partial waves. The maximal asymmetry after summing over all
the angular modes is only around $10^{-8}$ above the ground. To achieve the
proposed asymmetry of $\mathcal{O}(10^{-4})$, a special geography may be needed
as the experimental site.
- Measurement of Solar $pp$ Neutrino Flux using Electron Recoil Data from
PandaX-4T Commissioning Run
2401.07045 [abs] [pdf]
[abstract]
by PandaX Collaboration, [and 91 more]Xiaoying Lu, Abdusalam Abdukerim, Zihao Bo, Wei Chen, Xun Chen, Yunhua Chen, Chen Cheng, Zhaokan Cheng, Xiangyi Cui, Yingjie Fan, Deqing Fang, Lisheng Geng, Karl Giboni, Xuyuan Guo, Chencheng Han, Ke Han, Changda He, Jinrong He, Di Huang, Junting Huang, Zhou Huang, Ruquan Hou, Yu Hou, Xiangdong Ji, Yonglin Ju, Chenxiang Li, Jiafu Li, Mingchuan Li, Shuaijie Li, Tao Li, Qing Lin, Jianglai Liu, Congcong Lu, Lingyin Luo, Yunyang Luo, Wenbo Ma, Yugang Ma, Yajun Mao, Yue Meng, Xuyang Ning, Binyu Pang, Ningchun Qi, Zhicheng Qian, Xiangxiang Ren, Nasir Shaheed, Xiaofeng Shang, Xiyuan Shao, Guofang Shen, Manbin Shen, Lin Si, Wenliang Sun, Yi Tao, Anqing Wang, Meng Wang, Qiuhong Wang, Shaobo Wang, Siguang Wang, Wei Wang, Xiuli Wang, Xu Wang, Zhou Wang, Yuehuan Wei, Mengmeng Wu, Weihao Wu, Yuan Wu, Mengjiao Xiao, Xiang Xiao, Kaizhi Xiong, Binbin Yan, Xiyu Yan, Yong Yang, Chunxu Yu, Ying Yuan, Zhe Yuan, Youhui Yun, Xinning Zeng, Minzhen Zhang, Peng Zhang, Shibo Zhang, Shu Zhang, Tao Zhang, Wei Zhang, Yang Zhang, Yingxin Zhang, Yuanyuan Zhang, Li Zhao, Jifang Zhou, Ning Zhou, Xiaopeng Zhou, Yubo Zhou, and Zhizhen Zhou [hide authors].
The proton-proton ($pp$) fusion chain dominates the neutrino production from
the Sun. The uncertainty of the predicted $pp$ neutrino flux is at the
sub-percent level, whereas that of the best measurement is $\mathcal{O}(10\%)$.
In this paper, we present the first result to measure the solar $pp$ neutrinos
in the electron recoil energy range from 24 to 144 keV, using the PandaX-4T
commissioning data with 0.63 tonne$\times$year exposure. The $pp$ neutrino flux
is determined to be $(8.0 \pm 3.9 \,{\rm{(stat)}} \pm 10.0 \,{\rm{(syst)}}
)\times 10^{10}\, $$\rm{s}^{-1} \rm{cm}^{-2}$, consistent with Standard Solar
Model and existing measurements, corresponding to a flux upper limit of
$23.3\times 10^{10}\, $$\rm{s}^{-1} \rm{cm}^{-2}$ at 90\% C.L..
- Charged-current non-standard neutrino interactions at Daya Bay
2401.02901 [abs] [pdf]
[abstract]
by Daya Bay collaboration, [and 201 more]F. P. An, W. D. Bai, A. B. Balantekin, M. Bishai, S. Blyth, G. F. Cao, J. Cao, J. F. Chang, Y. Chang, H. S. Chen, H. Y. Chen, S. M. Chen, Y. Chen, Y. X. Chen, Z. Y. Chen, J. Cheng, Y. C. Cheng, Z. K. Cheng, J. J. Cherwinka, M. C. Chu, J. P. Cummings, O. Dalager, F. S. Deng, X. Y. Ding, Y. Y. Ding, M. V. Diwan, T. Dohnal, D. Dolzhikov, J. Dove, K. V. Dugas, H. Y. Duyang, D. A. Dwyer, J. P. Gallo, M. Gonchar, G. H. Gong, H. Gong, W. Q. Gu, J. Y. Guo, L. Guo, X. H. Guo, Y. H. Guo, Z. Guo, R. W. Hackenburg, Y. Han, S. Hans, M. He, K. M. Heeger, Y. K. Heng, Y. K. Hor, Y. B. Hsiung, B. Z. Hu, J. R. Hu, T. Hu, Z. J. Hu, H. X. Huang, J. H. Huang, X. T. Huang, Y. B. Huang, P. Huber, D. E. Jaffe, K. L. Jen, X. L. Ji, X. P. Ji, R. A. Johnson, D. Jones, L. Kang, S. H. Kettell, S. Kohn, M. Kramer, T. J. Langford, J. Lee, J. H. C. Lee, R. T. Lei, R. Leitner, J. K. C. Leung, F. Li, H. L. Li, J. J. Li, Q. J. Li, R. H. Li, S. Li, S. Li, S. C. Li, W. D. Li, X. N. Li, X. Q. Li, Y. F. Li, Z. B. Li, H. Liang, C. J. Lin, G. L. Lin, S. Lin, J. J. Ling, J. M. Link, L. Littenberg, B. R. Littlejohn, J. C. Liu, J. L. Liu, J. X. Liu, C. Lu, H. Q. Lu, K. B. Luk, B. Z. Ma, X. B. Ma, X. Y. Ma, Y. Q. Ma, R. C. Mandujano, C. Marshall, K. T. McDonald, R. D. McKeown, Y. Meng, J. Napolitano, D. Naumov, E. Naumova, T. M. T. Nguyen, J. P. Ochoa-Ricoux, A. Olshevskiy, J. Park, S. Patton, J. C. Peng, C. S. J. Pun, F. Z. Qi, M. Qi, X. Qian, N. Raper, J. Ren, C. Morales Reveco, R. Rosero, B. Roskovec, X. C. Ruan, B. Russell, H. Steiner, J. L. Sun, T. Tmej, W. -H. Tse, C. E. Tull, Y. C. Tung, B. Viren, V. Vorobel, C. H. Wang, J. Wang, M. Wang, N. Y. Wang, R. G. Wang, W. Wang, X. Wang, Y. F. Wang, Z. Wang, Z. Wang, Z. M. Wang, H. Y. Wei, L. H. Wei, W. Wei, L. J. Wen, K. Whisnant, C. G. White, H. L. H. Wong, E. Worcester, D. R. Wu, Q. Wu, W. J. Wu, D. M. Xia, Z. Q. Xie, Z. Z. Xing, H. K. Xu, J. L. Xu, T. Xu, T. Xue, C. G. Yang, L. Yang, Y. Z. Yang, H. F. Yao, M. Ye, M. Yeh, B. L. Young, H. Z. Yu, Z. Y. Yu, B. B. Yue, V. Zavadskyi, S. Zeng, Y. Zeng, L. Zhan, C. Zhang, F. Y. Zhang, H. H. Zhang, J. L. Zhang, J. W. Zhang, Q. M. Zhang, S. Q. Zhang, X. T. Zhang, Y. M. Zhang, Y. X. Zhang, Y. Y. Zhang, Z. J. Zhang, Z. P. Zhang, Z. Y. Zhang, J. Zhao, R. Z. Zhao, L. Zhou, H. L. Zhuang, and J. H. Zou [hide authors].
The full data set of the Daya Bay reactor neutrino experiment is used to
probe the effect of the charged current non-standard interactions (CC-NSI) on
neutrino oscillation experiments. Two different approaches are applied and
constraints on the corresponding CC-NSI parameters are obtained with the
neutrino flux taken from the Huber-Mueller model with a $5\%$ uncertainty. For
the quantum mechanics-based approach (QM-NSI), the constraints on the CC-NSI
parameters $\epsilon_{e\alpha}$ and $\epsilon_{e\alpha}^{s}$ are extracted with
and without the assumption that the effects of the new physics are the same in
the production and detection processes, respectively. The approach based on the
weak effective field theory (WEFT-NSI) deals with four types of CC-NSI
represented by the parameters $[\varepsilon_{X}]_{e\alpha}$. For both
approaches, the results for the CC-NSI parameters are shown for cases with
various fixed values of the CC-NSI and the Dirac CP-violating phases, and when
they are allowed to vary freely. We find that constraints on the QM-NSI
parameters $\epsilon_{e\alpha}$ and $\epsilon_{e\alpha}^{s}$ from the Daya Bay
experiment alone can reach the order $\mathcal{O}(0.01)$ for the former and
$\mathcal{O}(0.1)$ for the latter, while for WEFT-NSI parameters
$[\varepsilon_{X}]_{e\alpha}$, we obtain $\mathcal{O}(0.1)$ for both cases.
- Correlations and Distinguishability Challenges in Supernova Models:
Insights from Future Neutrino Detectors
2401.02531 [abs] [pdf]
[abstract]
by Maria Manuela Saez, [and 4 more]Ermal Rrapaj, Akira Harada, Shigehiro Nagataki, and Yong-Zhong Qian [hide authors].
This paper explores core-collapse supernovae as crucial targets for neutrino
telescopes, addressing uncertainties in their simulation results. We
comprehensively analyze eighteen modern simulations and discriminate among
supernova models using realistic detectors and interactions. A significant
correlation between the total neutrino energy and cumulative counts, driven by
massive lepton neutrinos and oscillations, is identified, particularly
noticeable with the DUNE detector. Bayesian techniques indicate strong
potential for model differentiation during a Galactic supernova event, with HK
excelling in distinguishing models based on equation of state, progenitor mass,
and mixing scheme.
- Non-standard neutrino interactions mediated by a light scalar at DUNE
2401.02107 [abs] [pdf]
[abstract]
by Bhaskar Dutta, [and 5 more]Sumit Ghosh, Kevin J. Kelly, Tianjun Li, Adrian Thompson, and Ankur Verma [hide authors].
We investigate the effect on neutrino oscillations generated by
beyond-the-standard-model interactions between neutrinos and matter.
Specifically, we focus on scalar-mediated non-standard interactions (NSI) whose
impact fundamentally differs from that of vector-mediated NSI. Scalar NSI
contribute as corrections to the neutrino mass matrix rather than the matter
potential and thereby predict distinct phenomenology from the vector-mediated
ones. Similar to vector-type NSI, the presence of scalar-mediated neutrino NSI
can influence measurements of oscillation parameters in long-baseline neutrino
oscillation experiments, with a notable impact on CP measurement in the case of
DUNE. Our study focuses on the effect of scalar NSI on neutrino oscillations,
using DUNE as an example. We introduce a model-independent parameterization
procedure that enables the examination of the impact of all non-zero scalar NSI
parameters simultaneously. Subsequently, we convert DUNE's sensitivity to the
NSI parameters into projected sensitivity concerning the parameters of a light
scalar model. We compare these results with existing non-oscillation probes.
Our findings reveal that the region of the light scalar parameter space
sensitive to DUNE is predominantly excluded by non-oscillation probes, except
for scenarios with very light mediator mass.
December 2023
- Solar neutrino constraints on light mediators through coherent elastic
neutrino-nucleus scattering
2312.17502 [abs] [pdf]
[abstract]
by Mehmet Demirci and M. Fauzi Mustamin.
We investigate new physics with light-neutral mediators through coherent
elastic neutrino-nucleus scattering (CE$\nu$NS) at low energies. These
mediators, with a mass of less than $1$ GeV, are common properties for
extensions of the Standard Model (SM). We consider general scalar, vector, and
tensor interactions allowed by Lorentz invariance and involve universal light
mediators accordingly. In addition, we study an additional vector gauge boson
with an associated $U(1)'$ gauge group for a variety of models including
$U(1)_{B-L}$, $U(1)_{B-3L_e}$, $U(1)_{B-3L_\mu}$, and $U(1)_{B-3L_\tau}$. These
models differ in the fermion charges, which determine their contributions
within the CE$\nu$NS process. The effects of each model are investigated by
embedding them in the SM process using solar neutrino flux. We derive new
limits on the coupling-mass plane of these models from the latest CDEX-10 data.
We also present projected sensitivities involving the future experimental
developments for each model. Our results provide more stringent constraints in
some regions, compared to previous works. Furthermore, the projected
sensitivities yield an improvement of up to one order of magnitude.
- Flavor Matters, but Matter Flavors: Matter Effects on Flavor Composition
of Astrophysical Neutrinos
2312.17315 [abs] [pdf]
[abstract]
by P. S. Bhupal Dev, Sudip Jana, and Yago Porto.
We show that high-energy astrophysical neutrinos produced in the cores of
heavily obscured active galactic nuclei (AGNs) can undergo strong matter
effects, thus significantly influencing their source flavor ratios. In
particular, matter effects can completely modify the standard interpretation of
the flavor ratio measurements in terms of the physical processes occurring in
the sources (e.g., $pp$ versus $p\gamma$, full pion-decay chain versus
muon-damped pion decay). We contrast our results with the existing flavor ratio
measurements at IceCube, as well as with projections for next-generation
neutrino telescopes like IceCube-Gen2. Signatures of these matter effects in
neutrino flavor composition would not only bring more evidence for neutrino
production in central AGN regions, but would also be a powerful probe of
heavily Compton-thick AGNs, which escape conventional observation in $X$-rays
and other electromagnetic wavelengths.
- Neutrino Mass Measurement with Cosmic Gravitational Focusing
2312.16972 [abs] [pdf]
[abstract]
by Shao-Feng Ge, Pedro Pasquini, and Liang Tan.
We thoroughly explore the cosmic gravitational focusing of cosmic neutrino
fluid (C$\nu$F) by dark matter (DM) halo using both general relativity for a
point source of gravitational potential and Boltzmann equations for continuous
overdensities. Derived in the general way for both relativistic and
non-relativistic neutrinos, our results show that the effect has fourth power
dependence on the neutrino mass and temperature. With nonlinear mass dependence
which is different from the cosmic microwave background (CMB) and large scale
structure (LSS) observations, the cosmic gravitational focusing can provide an
independent cosmological way of measuring the neutrino mass and ordering. We
take DESI as an example to illustrate that the projected sensitivity as well as
its synergy with existing terrestrial neutrino oscillation experiments and
other cosmological observations can significantly improve the neutrino mass
measurement.
- Neutrino Lorentz Invariance Violation from Cosmic Fields
2312.16320 [abs] [pdf]
[abstract]
by Rubén Cordero and Luis A. Delgadillo.
From a cosmological perspective, scalar fields are well-motivated dark matter
and dark energy candidates. Several possibilities of neutrino couplings with a
time-varying cosmic field have been investigated in the literature. In this
work, we present a framework in which violations of Lorentz invariance (LIV)
and $CPT$ symmetry in the neutrino sector could arise from an interaction among
neutrinos with a time-varying scalar field. Furthermore, some cosmological and
phenomenological aspects and constraints concerning this type of interaction
are discussed. Potential violations of Lorentz and $CPT$ symmetries at present
and future neutrino oscillation experiments such as IceCube and KM3NeT can
probe this scenario.
- Constraints on sterile neutrinos and the cosmological tensions
2312.15435 [abs] [pdf]
[abstract]
by Supriya Pan, [and 3 more]Osamu Seto, Tomo Takahashi, and Yo Toda [hide authors].
We investigate cosmological bounds on sterile neutrino masses in the light of
the Hubble and $S_8$ tensions. We argue that non-zero masses for sterile
neutrinos are inferred at 2$\sigma$ level in some extended models such as
varying dark energy equation of state, when a direct measurement of the Hubble
constant $H_0$ and weak lensing measurement of dark energy survey (DES) are
taken into account. Furthermore, the Hubble and $S_8$ tensions are also reduced
in such a framework. We also consider the case where a non-flat Universe is
allowed and show that a slightly open Universe may be favored in models with
sterile neutrinos in the context of the cosmological tensions.
- Connecting Tribimaximal and Bitrimaximal Mixings
2312.15391 [abs] [pdf]
[abstract]
by Carlos Alvarado, Janelly Bautista, and Alexander J. Stuart.
In this paper, we study the connection between the tribimaximal and
bitrimaximal mixing patterns. In doing so, we are forced to work in a
non-diagonal charged lepton basis. This leads to several relations that must
hold between the lepton mixing angles. After a short discussion, we analyze the
underlying flavor symmetry responsible for this prediction. Finally, we add CP
violation to bitrimaximal mixing and study its effect on the flavor symmetry
group.
- Neutrino masses from new seesaw models: Low-scale variants and
phenomenological implications
2312.14119 [abs] [pdf]
[abstract]
by Alessio Giarnetti, [and 4 more]Juan Herrero-Garcia, Simone Marciano, Davide Meloni, and Drona Vatsyayan [hide authors].
With just the Standard Model Higgs doublet, there are only three types of
seesaw models that generate light Majorana neutrino masses at tree level after
electroweak spontaneous symmetry breaking. However, if there exist additional
TeV scalars acquiring vacuum expectation values, coupled with heavier fermionic
multiplets, several new seesaw models become possible. These new seesaws are
the primary focus of this study and correspond to the tree-level ultraviolet
completions of the effective operators studied in a companion publication. We
are interested in the genuine cases, in which the standard seesaw contributions
are absent. In addition to the tree-level generation of neutrino masses, we
also consider the one-loop contributions. Furthermore, we construct low-energy
versions that exhibit a very rich phenomenology. Specifically, we scrutinise
the generation of dimension-6 operators and explore their implications,
including non-unitarity of the leptonic mixing matrix, non-universal $Z-$boson
interactions, and lepton flavor violation. Finally, we provide (Generalised)
Scotogenic-like variants that incorporate viable dark matter candidates.
- Limits on heavy neutral leptons, $Z'$ bosons and majorons from
high-energy supernova neutrinos
2312.13627 [abs] [pdf]
[abstract]
by Kensuke Akita, [and 3 more]Sang Hui Im, Mehedi Masud, and Seokhoon Yun [hide authors].
Light hypothetical particles with masses up to $\mathcal{O}(100)\ {\rm MeV}$
can be produced in the core of supernovae. Their subsequent decays to neutrinos
can produce a flux component with higher energies than the standard flux. We
study the impact of heavy neutral leptons, $Z'$ bosons, in particular ${\rm
U(1)}_{L_\mu-L_\tau}$ and ${\rm U(1)}_{B-L}$ gauge bosons, and majorons coupled
to neutrinos flavor-dependently. We obtain new strong limits on these particles
from no events of high-energy SN 1987A neutrinos and their future sensitivities
from observations of galactic supernova neutrinos.
- Photons from neutrinos: the gamma ray echo of a supernova neutrino burst
2312.13197 [abs] [pdf]
[abstract]
by Cecilia Lunardini, [and 5 more]Joshua Loeffler, Mainak Mukhopadhyay, Matthew J. Hurley, Ebraheem Farag, and F. X. Timmes [hide authors].
When a star undergoes core collapse, a vast amount of energy is released in a
~10 s long burst of neutrinos of all species. Inverse beta decay in the star's
hydrogen envelope causes an electromagnetic cascade which ultimately results in
a flare of gamma rays - an "echo" of the neutrino burst - at the characteristic
energy of 0.511 MeV. We study the phenomenology and detectability of this
flare. Its luminosity curve is characterized by a fast, seconds-long, rise and
an equally fast decline, with a minute- or hour-long plateau in between. For a
near-Earth star (distance D<1 kpc) the echo will be observable at near future
gamma ray telescopes with an effective area of 10^3 cm^2 or larger. Its
observation will inform us on the envelope size and composition. In conjunction
with the direct detection of the neutrino burst, it will also give information
on the neutrino emission away from the line of sight and will enable tests of
neutrino propagation effects between the stellar surface and Earth.
- Solar neutrino measurements using the full data period of
Super-Kamiokande-IV
2312.12907 [abs] [pdf]
[abstract]
by Super-Kamiokande Collaboration, [and 329 more]:, K. Abe, C. Bronner, Y. Hayato, K. Hiraide, K. Hosokawa, K. Ieki, M. Ikeda, S. Imaizumi, K. Iyogi, J. Kameda, Y. Kanemura, R. Kaneshima, Y. Kashiwagi, Y. Kataoka, Y. Kato, Y. Kishimoto, S. Miki, S. Mine, M. Miura, T. Mochizuki, S. Moriyama, Y. Nagao, M. Nakahata, Y. Nakano, S. Nakayama, Y. Noguchi, T. Okada, K. Okamoto, A. Orii, K. Sato, H. Sekiya, H. Shiba, K. Shimizu, M. Shiozawa, Y. Sonoda, Y. Suzuki, A. Takeda, Y. Takemoto, A. Takenaka, H. Tanaka, S. Watanabe, T. Yano, S. Han, T. Kajita, K. Okumura, T. Tashiro, T. Tomiya, R. Wang, X. Wang, S. Yoshida, D. Bravo-Berguno, P. Fernandez, L. Labarga, N. Ospina, B. Zaldivar, B. W. Pointon, F. d. M. Blaszczyk, C. Kachulis, E. Kearns, J. L. Raaf, J. L. Stone, L. Wan, T. Wester, J. Bian, N. J. Griskevich, W. R. Kropp, S. Locke, M. B. Smy, H. W. Sobel, V. Takhistov, P. Weatherly, A. Yankelevich, K. S. Ganezer, J. Hill, M. C. Jang, J. Y. Kim, S. Lee, I. T. Lim, D. H. Moon, R. G. Park, B. Bodur, K. Scholberg, C. W. Walter, A. Beauchene, L. Bernard, A. Coffani, O. Drapier, S. El Hedri, A. Giampaolo, J. Imber, Th. A. Mueller, P. Paganini, R. Rogly, B. Quilain, A. Santos, T. Nakamura, J. S. Jang, L. N. Machado, J. G. Learned, S. Matsuno, N. Iovine, K. Choi, S. Cao, L. H. V. Anthony, R. P. Litchfield, N. Prouse, D. Marin, M. Scott, A. A. Sztuc, Y. Uchida, V. Berardi, M. G. Catanesi, R. A. Intonti, E. Radicioni, N. F. Calabria, G. De Rosa, A. Langella, G. Collazuol, F. Iacob, M. Lamoureux, M. Mattiazzi, L. Ludovici, M. Gonin, L. Perisse, G. Pronost, C. Fujisawa, Y. Maekawa, Y. Nishimura, R. Okazaki, M. Friend, T. Hasegawa, T. Ishida, M. Jakkapu, T. Kobayashi, T. Matsubara, T. Nakadaira, K. Nakamura, Y. Oyama, K. Sakashita, T. Sekiguchi, T. Tsukamoto, T. Boschi, N. Bhuiyan, G. T. Burton, J. Gao, A. Goldsack, T. Katori, F. Di Lodovico, J. Migenda, S. Molina Sedgwick, R. M. Ramsden, M. Taani, Z. Xie, S. Zsoldos, KE. Abe, M. Hasegawa, Y. Isobe, Y. Kotsar, H. Miyabe, H. Ozaki, T. Shiozawa, T. Sugimoto, A. T. Suzuki, Y. Takagi, Y. Takeuchi, S. Yamamoto, H. Zhong, Y. Ashida, J. Feng, L. Feng, T. Hayashino, S. Hirota, J. R. Hu, Z. Hu, M. Jiang, M. Kawaue, T. Kikawa, M. Mori, KE. Nakamura, T. Nakaya, R. A. Wendell, K. Yasutome, S. J. Jenkins, N. McCauley, P. Mehta, A. Pritchard, A. Tarrant, M. J. Wilking, Y. Fukuda, Y. Itow, H. Menjo, M. Murase, K. Ninomiya, T. Niwa, M. Tsukada, Y. Yoshioka, K. Frankiewicz, J. Lagoda, M. Mandal, P. Mijakowski, Y. S. Prabhu, J. Zalipska, J. Jiang, M. Jia, C. K. Jung, J. L. Palomino, G. Santucci, W. Shi, C. Vilela, C. Yanagisawa, D. Fukuda, K. Hagiwara, M. Harada, Y. Hino, T. Horai, H. Ishino, S. Ito, H. Kitagawa, Y. Koshio, W. Ma, F. Nakanishi, N. Piplani, S. Sakai, M. Sakuda, T. Tada, T. Tano, C. Xu, R. Yamaguchi, T. Ishizuka, Y. Kuno, G. Barr, D. Barrow, L. Cook, S. Samani, C. Simpson, D. Wark, A. M. Holin, F. Nova, S. Jung, B. Yang, J. Y. Yang, J. Yoo, J. E. P. Fannon, L. Kneale, M. Malek, J. M. McElwee, O. Stone, M. D. Thiesse, L. F. Thompson, S. T. Wilson, H. Okazawa, S. M. Lakshmi, Y. Choi, S. B. Kim, E. Kwon, J. W. Seo, I. Yu, A. K. Ichikawa, K. Nakamura, S. Tairahune, K. Nishijima, A. Eguchi, K. Iwamoto, K. Nakagiri, Y. Nakajima, N. Ogawa, S. Shima, E. Watanabe, M. Yokoyama, R. G. Calland, S. Fujita, C. Jesus-Valls, X. Junjie, T. K. Ming, P. de Perio, K. Martens, M. Murdoch, M. R. Vagins, S. Izumiyama, M. Kuze, R. Matsumoto, Y. Okajima, M. Tanaka, T. Yoshida, M. Inomoto, M. Ishitsuka, H. Ito, T. Kinoshita, R. Matsumoto, K. Ohta, Y. Ommura, M. Shinoki, N. Shigeta, T. Suganuma, K. Yamaguchi, T. Yoshida, J. F. Martin, C. M. Nantais, H. A. Tanaka, T. Towstego, R. Gaur, V. Gousy-Leblanc, M. Hartz, A. Konaka, X. Li, S. Chen, B. D. Xu, B. Zhang, S. Berkman, M. Posiadala-Zezula, S. B. Boyd, R. Edwards, D. Hadley, M. Nicholson, M. O'Flaherty, B. Richards, A. Ali, B. Jamieson, J. Walker, S. Amanai, Ll. Marti, A. Minamino, K. Okamoto, G. Pintaudi, S. Sano, R. Sasaki, S. Suzuki, and K. Wada [hide authors].
An analysis of solar neutrino data from the fourth phase of
Super-Kamiokande~(SK-IV) from October 2008 to May 2018 is performed and the
results are presented. The observation time of the data set of SK-IV
corresponds to $2970$~days and the total live time for all four phases is
$5805$~days. For more precise solar neutrino measurements, several improvements
are applied in this analysis: lowering the data acquisition threshold in May
2015, further reduction of the spallation background using neutron clustering
events, precise energy reconstruction considering the time variation of the PMT
gain. The observed number of solar neutrino events in $3.49$--$19.49$ MeV
electron kinetic energy region during SK-IV is
$65,443^{+390}_{-388}\,(\mathrm{stat.})\pm 925\,(\mathrm{syst.})$ events.
Corresponding $\mathrm{^{8}B}$ solar neutrino flux is $(2.314 \pm 0.014\,
\rm{(stat.)} \pm 0.040 \, \rm{(syst.)}) \times
10^{6}~\mathrm{cm^{-2}\,s^{-1}}$, assuming a pure electron-neutrino flavor
component without neutrino oscillations. The flux combined with all SK phases
up to SK-IV is $(2.336 \pm 0.011\, \rm{(stat.)} \pm 0.043 \, \rm{(syst.)})
\times 10^{6}~\mathrm{cm^{-2}\,s^{-1}}$. Based on the neutrino oscillation
analysis from all solar experiments, including the SK $5805$~days data set, the
best-fit neutrino oscillation parameters are $\rm{sin^{2} \theta_{12,\,solar}}
= 0.306 \pm 0.013 $ and $\Delta m^{2}_{21,\,\mathrm{solar}} = (6.10^{+
0.95}_{-0.81}) \times 10^{-5}~\rm{eV}^{2}$, with a deviation of about
1.5$\sigma$ from the $\Delta m^{2}_{21}$ parameter obtained by KamLAND. The
best-fit neutrino oscillation parameters obtained from all solar experiments
and KamLAND are $\sin^{2} \theta_{12,\,\mathrm{global}} = 0.307 \pm 0.012 $ and
$\Delta m^{2}_{21,\,\mathrm{global}} = (7.50^{+ 0.19}_{-0.18}) \times
10^{-5}~\rm{eV}^{2}$.
- Searching for Axial Neutral Current Non-Standard Interactions of
neutrinos by DUNE-like experiments
2312.12420 [abs] [pdf]
[abstract]
by Saeed Abbaslu, [and 3 more]Mehran Dehpour, Yasaman Farzan, and Sahar Safari [hide authors].
The increasingly precise neutrino experiments raise the hope for searching
for new physics through studying the impact of Neutral Current (NC)
Non-Standard Interactions (NSI) of neutrinos with matter fields. Neutrino
oscillation experiments along with the Elastic Coherent $\nu$ Nucleus
Scattering (CE$\nu$NS) experiments already set strong bounds on all the flavor
elements of the "vector" NC NSI. However, "axial" NC NSI can hide from these
experiments. We show how a DUNE-like experiment can probe these couplings by
studying NC Deep Inelastic Scattering (DIS) events. We find that strong bounds
can be set on the axial NC NSI of neutrinos with the $u$, $d$, and $s$ quarks.
We show that using both the near and far detectors, a DUNE-like experiment can
significantly improve the present bounds on all the flavor elements.
- Primordial Black Hole Sterile Neutrinogenesis: Sterile Neutrino Dark
Matter Production Independent of Couplings
2312.12136 [abs] [pdf]
[abstract]
by Muping Chen, [and 3 more]Graciela B. Gelmini, Philip Lu, and Volodymyr Takhistov [hide authors].
Sterile neutrinos ($\nu_s$s) are well-motivated and actively searched for
hypothetical neutral particles that would mix with the Standard Model active
neutrinos. They are considered prime warm dark matter (DM) candidates,
typically when their mass is in the keV range, although they can also be hot or
cold DM components. We discuss in detail the characteristics and phenomenology
of $\nu_s$s that minimally couple only to active neutrinos and are produced in
the evaporation of early Universe primordial black holes (PBHs), a process we
called "PBH sterile neutrinogenesis". Contrary to the previously studied
$\nu_s$ production mechanisms, this novel mechanism does not depend on the
active-sterile mixing. The resulting $\nu_s$s have a distinctive spectrum and
are produced with larger energies than in typical scenarios. This
characteristic enables $\nu_s$s to be WDM in the unusual $0.3$ MeV to $0.3$ TeV
mass range, if PBHs do not matter-dominate the Universe before evaporating.
When PBHs matter-dominate before evaporating, the possible coincidence of
induced gravitational waves associated with PBH evaporation and astrophysical
X-ray observations from $\nu_s$ decays constitutes a distinct signature of our
scenario. constitutes a distinct signature of our scenario.
- Ultralight dark matter in neutrino oscillations to accommodate T2K and
NO$ν$A tension
2312.11704 [abs] [pdf]
[abstract]
by Hai-Xing Lin, Jian Tang, and Sampsa Vihonen.
Ultralight dark matter with neutrino couplings is investigated in light of
the long-baseline neutrino oscillation data in T2K and NO$\nu$A experiments.
The observed tension between T2K and NO$\nu$A is shown to be ameliorated when
ultralight dark matter of either scalar or vector form is taken into
consideration. The best result is achieved with scalar dark matter which can
alleviate the tension by 2.0$\sigma$ CL with flavour-universal couplings. We
also consider scalar dark matter with flavour-general couplings and vector dark
matter in $L_e - L_\mu$ and $L_\mu - L_\tau$ cases. It is shown in all cases
that the tension is relaxed by approximately 1.5$\sigma$-2.0$\sigma$ CL while
the current experimental constraints can be evaded.
- Superradiant Leptogenesis
2312.06768 [abs] [pdf]
[abstract]
by Anish Ghoshal, Yuber F. Perez-Gonzalez, and Jessica Turner.
We investigate how superradiance affects the generation of baryon asymmetry
in a universe with rotating primordial black holes, considering a scenario
where a scalar boson is coupled to the heavy right-handed neutrinos. We
identify the regions of the parameter space where the scalar production is
enhanced due to superradiance. This enhancement, coupled with the subsequent
decay of the scalar into right handed neutrinos, results in the non-thermal
creation of lepton asymmetry. We show that successful leptogenesis is achieved
for masses of primordial black holes in the range of order $O(0.1~{\rm g}) -
O(10~{\rm g})$ and the lightest of the heavy neutrino masses, $M_N \sim
O(10^{12})~{\rm GeV}$. Consequently, regions of the parameter space, which in
the case of Schwarzchild PBHs were incompatible with viable leptogenesis, can
produce the observed matter-antimatter asymmetry.
- Sensitivity floor for primordial black holes with neutrino searches
2312.06108 [abs] [pdf]
[abstract]
by Qishan Liu and Kenny C. Y. Ng.
Primordial black holes~(PBHs) formed in the early Universe are well-motivated
dark matter~(DM) candidates over a wide range of masses. These PBHs could emit
detectable signals in the form of photons, electrons, and neutrinos through
Hawking radiation. We consider the null observations of astrophysical
$\bar{\nu}_{e}$ flux from several neutrino detectors and set new constraints on
the PBHs as the dominant DM component to be above $6.4\times10^{15}\,{\rm g}$.
We also estimate the expected constraints with JUNO for the prospects in the
near future. Lastly, we note that the diffuse supernova neutrino
background~(DSNB) is an unavoidable isotropic background. We thus estimate the
sensitivity floor for PBH parameter space due to the DSNB and show that it is
challenging for neutrino detectors to identify PBHs as they constitute 100\% of
the DM above a mass of 9$\times10^{15}$g.
- Relic neutrino decay solution to the excess radio background
2312.03082 [abs] [pdf]
[abstract]
by P. S. Bhupal Dev, [and 3 more]Pasquale Di Bari, Ivan Martínez-Soler, and Rishav Roshan [hide authors].
The excess radio background detected by ARCADE 2 represents a puzzle within
the standard cosmological model. There is no clear viable astrophysical
solution, and therefore, it might indicate the presence of new physics.
Radiative decays of a relic neutrino $\nu_i$ (either $i=1$, or $i=2$, or $i=3$)
into a sterile neutrino $\nu_{\rm s}$, assumed to be quasi-degenerate, provide
a solution that currently evades all constraints posed by different
cosmological observations and reproduces very well the ARCADE 2 data. We find a
very good fit to the ARCADE 2 data with best fit values $\tau_i = 1.46 \times
10^{21}\,{\rm s}$ and $\Delta m_i = 4.0 \times 10^{-5}\,{\rm eV}$, where
$\tau_i$ is the lifetime and $\Delta m_i$ is the mass difference between the
decaying active neutrino and the sterile neutrino. On the other hand, if relic
neutrino decays do not explain ARCADE 2 data, then these place a stringent
constraint $\Delta m_i^{3/2} \tau_i \gtrsim 2 \times 10^{14}\,{\rm
eV}^{3/2}\,{\rm s}$ in the range $1.4 \times 10^{-5} \, {\rm eV} < \Delta m_i <
2.5 \times 10^{-4}\,{\rm eV}$. The solution also predicts a stronger 21 cm
absorption global signal than the predicted one from the $\Lambda$CDM model,
with a contrast brightness temperature $T_{21} = -238^{+21}_{-20}\,{\rm mK}$
($99\%$ C.L.) at redshift $z\simeq 17$. This is in mild tension with the even
stronger signal found by the EDGES collaboration, $T_{21} = -
500^{+200}_{-500}\,{\rm mK} $, suggesting that this might have been
overestimated, possibly receiving a contribution from some unidentified
foreground source.
- Constraints on UHECR sources and extragalactic magnetic fields from
directional anisotropies
2312.02645 [abs] [pdf]
[abstract]
by Teresa Bister and Glennys R. Farrar.
A dipole anisotropy in ultra-high-energy cosmic ray (UHECR) arrival
directions, of extragalactic origin, is now firmly established at energies E >
8 EeV. Furthermore, the UHECR angular power spectrum shows no power at smaller
angular scales than the dipole, apart from hints of possible individual hot or
warm spots for energy thresholds $\gtrsim$40 EeV. Here, we exploit the
magnitude of the dipole and the limits on smaller-scale anisotropies to place
constraints on two quantities: the extragalactic magnetic field (EGMF) and the
number density of UHECR sources or the volumetric event rate if UHECR sources
are transient. We also vary the bias between the extragalactic matter and the
UHECR source densities, reflecting whether UHECR sources are preferentially
found in over- or under-dense regions, and find that little or no bias is
favored. We follow Ding et al. (2021) in using the Cosmic Flows 2 density
distribution of the local universe as our baseline distribution of UHECR
sources, but we improve and extend that work by employing an accurate and
self-consistent treatment of interactions and energy losses during propagation.
Deflections in the Galactic magnetic field are treated using both the full JF12
magnetic field model, with random as well as coherent components, or just the
coherent part, to bracket the impact of the GMF on the dipole anisotropy. This
Large Scale Structure (LSS) model gives good agreement with both the direction
and magnitude of the measured dipole anisotropy and forms the basis for
simulations of discrete sources and the inclusion of EGMF effects.
- The Targets of Opportunity Source Catalog for the EUSO-SPB2 Mission
2312.00920 [abs] [pdf]
[abstract]
by Hannah Wistrand, [and 5 more]Tobias Heibges, Jonatan Posligua, Claire Guepin, Mary Hall Reno, and Tonia M. Venters [hide authors].
The Extreme Universe Space Observatory on a Super Pressure Balloon 2, EUSO
SPB2, mission was designed to take optical measurements of extensive air
showers, EASs, from suborbital space. The EUSO SPB2 payload includes an optical
Cherenkov Telescope, CT, which searches above and below the Earth's limb. Above
the limb, the CT measures Cherenkov light from PeV scale EASs induced by cosmic
rays. Below the limb, the CT searches for upwards going Cherenkov emission from
PeV scale EASs induced by tau neutrinos, to follow up on astrophysical Targets
of Opportunity, ToO. Target candidates include gamma ray bursts, tidal
disruption events, and, after the start of the O4 obervation run from Ligo,
Virgo, Kagra, binary neutron star mergers. Reported here is the selection and
prioritization of relevant ToOs from alert networks such as the General
Coordinates Network, Transient Name Server, and Astronomer Telegrams, and the
translation to a viewing schedule for EUSO SPB2. EUSO SPB2 launched on a NASA
super pressure balloon in May of 2023 from Wanaka, NZ.
- Confronting solutions of the Gallium Anomaly with reactor rate data
2312.00565 [abs] [pdf]
[abstract]
by Carlo Giunti and Christoph A. Ternes.
Recently, several models have been suggested to reduce the tension between
Gallium and reactor antineutrino spectral ratio data which is found in the
framework of 3+1 active-sterile neutrino mixing. Among these models, we
consider the extensions of 3+1 mixing with a finite wavepacket size, or the
decay of the heaviest neutrino $\nu_4$, or the possibility to have a broad
$\nu_4$ mass distribution. We consider the reactor antineutrino rate data and
we show that these models cannot liminate the tension between Gallium and
reactor rate data that is found in the 3+1 neutrino mixing framework. Indeed,
we show that the parameter goodness of fit remains small. We consider also a
model which explains the Gallium Anomaly with non-standard decoherence in the
framework of three-neutrino mixing. We find that it is compatible with the
reactor rate data.
November 2023
- Search for Hidden Neutrinos at the European Spallation Source: the
SHiNESS experiment
2311.18509 [abs] [pdf]
[abstract]
by Stefano Roberto Soleti, [and 3 more]Pilar Coloma, Juan Jose Gómez Cadenas, and Anatael Cabrera [hide authors].
The upcoming European Spallation Source (ESS) will soon provide the most
intense neutrino source in the world. We propose the Search for Hidden
Neutrinos at the ESS (SHiNESS) experiment, highlighting its unique
opportunities to search for the existence of sterile neutrinos across a wide
range of scales: anomalous oscillations at short baselines; non-unitarity
mixing in the active neutrino sector; or an excess of events with multiple
leptons in the final state, produced in the decay of heavy neutrinos. The
baseline design of the detector comprises an active volume filled with 42 ton
of liquid scintillator, located 25 m far from the ESS beam target. We show that
SHiNESS will be able to considerably improve current global limits for the
three cases outlined above. Although in this work we focus on new physics in
the neutrino sector, the proposed setup may also be used to search for signals
from weakly interacting particles in a broader context.
- Status of Direct Determination of Solar Neutrino Fluxes after Borexino
2311.16226 [abs] [pdf]
[abstract]
by M. C. Gonzalez-Garcia, [and 3 more]Michele Maltoni, João Paulo Pinheiro, and Aldo M. Serenelli [hide authors].
We determine the solar neutrino fluxes from the global analysis of the most
up-to-date terrestrial and solar neutrino data including the final results of
the three phases of Borexino. The analysis are performed in the framework of
three-neutrino mixing with and without accounting for the solar luminosity
constraint. We discuss the independence of the results on the input from the
Gallium experiments. The determined fluxes are then compared with the
predictions provided by the latest Standard Solar Models. We quantify the
dependence of the model comparison with the assumptions about the normalization
of the solar neutrino fluxes produced in the CNO-cycle as well as on the
particular set of fluxes employed for the model testing.
- Uncovering Secret Neutrino Interactions at Tau Neutrino Experiments
2311.14945 [abs] [pdf]
[abstract]
by Pouya Bakhti, Meshkat Rajaee, and Seodong Shin.
We investigate the potential of future tau neutrino experiments for
identifying the $\nu_\tau$ appearance in probing secret neutrino interactions.
The reference experiments include the DUNE far detector utilizing the
atmospheric data, which is for the first time in probing the secret
interactions, the Forward Liquid Argon Experiment (FLArE100) detector at the
Forward Physics Facility (FPF), and emulsion detector experiments such as
SND@LHC, AdvSND, FASER$\nu$2, and SND@SHiP. For concreteness, we consider a
reference scenario in which the hidden interactions among the neutrinos are
mediated by a single light gauge boson $Z'$ with a mass at most below the
sub-GeV scale and an interaction strength $g_{\alpha \beta}$ between the active
neutrinos. We confirm that these experiments have the capability to
significantly enhance the current sensitivities on $g_{\alpha \beta }$ for
$m_{Z'} \lesssim 500$ MeV due to the production of high energy neutrinos and
excellent ability to detect tau neutrinos. Our analysis highlights the crucial
role of downward-going DUNE atmospheric data in the search for secret neutrino
interactions because of the rejection of backgrounds dominated in the
upward-going events. Specifically, 10 years of DUNE atmospheric data can
provide the best sensitivities on $g_{\alpha \beta}$ which is about two orders
of magnitude improvement. In addition, the beam-based experiments such as
FLArE100 and FASER$\nu$2 can improve the current constraint on $g_{e\tau}$ and
$g_{\mu\tau}$ by more than an order of magnitude after the full running of the
high luminosity LHC with the integrated luminosity of 3 ab$^{-1}$. For
$g_{e\mu}$ and $g_{ee}$ the SHiP experiment can play the most important role in
the high energy region of $E> few~100$ MeV.
- Relaxing cosmological constraints on current neutrino masses
2311.01803 [abs] [pdf]
[abstract]
by Vitor da Fonseca, Tiago Barreiro, and Nelson J. Nunes.
We show that a mass-varying neutrino model driven by scalar field dark energy
relaxes the existing upper bound on the current neutrino mass to ${\sum m_\nu <
0.72}$ eV. We extend the standard $\Lambda$ cold dark matter model by
introducing two parameters: the rate of change of the scalar field with the
number of $e$-folds and the coupling between neutrinos and the field. We
investigate how they affect the matter power spectrum, the cosmic microwave
background anisotropies and its lensing potential. The model is tested against
Planck observations of temperature, polarization, and lensing, combined with
baryon acoustic oscillation measurements that constrain the background
evolution. The results indicate that small couplings favor a cosmological
constant, while larger couplings favor a dynamical dark energy, weakening the
upper bound on current neutrino masses.
- New Signal of Atmospheric Tau Neutrino Appearance: Sub-GeV
Neutral-Current Interactions in JUNO
2311.01667 [abs] [pdf]
[abstract]
by Stephan A. Meighen-Berger, [and 3 more]John F. Beacom, Nicole F. Bell, and Matthew J. Dolan [hide authors].
We propose the first practical method to detect atmospheric tau neutrino
appearance at sub-GeV energies, which would be an important test of $\nu_\mu
\rightarrow \nu_\tau$ oscillations and of new-physics scenarios. In the
Jiangmen Underground Neutrino Observatory (JUNO; starts in 2024), active-flavor
neutrinos eject neutrons from carbon via neutral-current quasielastic
scattering. This produces a two-part signal: the prompt part is caused by the
scattering of the neutron in the scintillator, and the delayed part by its
radiative capture. Such events have been observed in KamLAND, but only in small
numbers and were treated as a background. With $\nu_\mu \rightarrow \nu_\tau$
oscillations, JUNO should measure a clean sample of 55 events/yr; with simple
$\nu_\mu$ disappearance, this would instead be 41 events/yr, where the latter
is determined from Super-Kamiokande charged-current measurements at similar
neutrino energies. Implementing this method will require precise laboratory
measurements of neutrino-nucleus cross sections or other developments. With
those, JUNO will have $5\sigma$ sensitivity to tau-neutrino appearance in 5
years exposure, and likely sooner.
October 2023
- Comprehensive constraints on heavy sterile neutrinos from core-collapse
supernovae
2311.00033 [abs] [pdf]
[abstract]
by Pierluca Carenza, [and 4 more]Giuseppe Lucente, Leonardo Mastrototaro, Alessandro Mirizzi, and Pasquale Dario Serpico [hide authors].
Sterile neutrinos with masses up to $\mathcal{O} (100)$ MeV can be copiously
produced in a supernova (SN) core, through the mixing with active neutrinos. In
this regard the SN 1987A detection of neutrino events has been used to put
constraints on active-sterile neutrino mixing, exploiting the well-known SN
cooling argument. We refine the calculation of this limit including neutral
current interactions with nucleons, that constitute the dominant channel for
sterile neutrino production. We also include, for the first time, the charged
current interactions between sterile neutrinos and muons, relevant for the
production of sterile neutrinos mixed with muon neutrinos in the SN core. Using
the recent modified luminosity criterion, we extend the bounds to the case
where sterile states are trapped in the stellar core. Additionally, we study
the decays of heavy sterile neutrinos, affecting the SN explosion energy and
possibly producing a gamma-ray signal. We also illustrate the complementarity
of our new bounds with cosmological bounds and laboratory searches.
- Exploring Neutrino Mass Orderings through Supernova Neutrino Detection
2310.19939 [abs] [pdf]
[abstract]
by Maria Manuela Saez.
Core-collapse supernovae (SNe) are one of the most powerful cosmic sources of
neutrinos, with energies of several MeV. The emission of neutrinos and
antineutrinos of all flavors carries away the gravitational binding energy of
the compact remnant and drives its evolution from the hot initial to the cold
final states. Detecting these neutrinos from Earth and analyzing the emitted
signals present a unique opportunity to explore the neutrino mass ordering
problem. This research outlines the detection of neutrinos from SNe and their
relevance in understanding the neutrino mass ordering. The focus is on
developing a model-independent analysis strategy, achieved by comparing
distinct detection channels in large underground detectors. The objective is to
identify potential indicators of mass ordering within the neutrino sector.
Additionally, a thorough statistical analysis is performed on the anticipated
neutrino signals for both mass orderings. Despite uncertainties in supernova
explosion parameters, an exploration of the parameter space reveals an
extensive array of models with significant sensitivity to differentiate between
mass orderings. The assessment of various observables and their combinations
underscores the potential of forthcoming supernova observations in addressing
the neutrino mass ordering problem.
- Alleviating the present tension between T2K and NO$ν$A with neutrino
New Physics at source
2310.18401 [abs] [pdf]
[abstract]
by Adriano Cherchiglia, [and 5 more]Pedro Pasquini, O. L. G. Peres, F. F. Rodrigues, R. R. Rossi, and E. S. Souza [hide authors].
Since neutrino oscillation was observed, several experiments have been built
to measure its parameters. NO$\nu$A and T2K are two long-baseline experiments
dedicated to measuring mainly the mixing angle $\theta_{23}$, the charge-parity
conjugation phase $\delta_{\rm CP}$, and the mass ordering. However, there is a
tension in current data. The T2K allowed region is almost excluded by the
NO$\nu$A result at the $90\%$ confidence level. We propose a non-standard
interaction (NSI) in neutrino production to relieve this tension. The NSI is
computed through quantum field theory (QFT) formalism, where we derive
perturbative analytical formulae considering NSI in the pion decay. Within this
new approach, we can alleviate NO$\nu$A and T2K tension for a NSI complex
parameters of order $10^{-3}$. We show the new phase has a degeneracy to the
Dirac CP phase of the form $\delta_{\rm CP} \pm \phi= 1.5\pi$ being a possible
source of violation of charge-parity symmetry.
- Linking solar bosonic dark matter halos and active neutrinos
2310.14033 [abs] [pdf]
[abstract]
by Ilídio Lopes.
Our study investigates the complex interaction between active neutrinos and
the ultralight bosonic dark matter halo surrounding the Sun. This halo extends
over several solar radii due to the Sun's gravitational field, and we represent
it as a coherent oscillating classical field configuration of bosonic dark
matter particles that vary in time. Our investigation has revealed that, based
on the available solar neutrino flux data, these novel models do not surpass
the performance of the conventional neutrino flavour oscillation model.
Furthermore, we discuss how next-generation solar neutrino detectors have the
potential to provide evidence for the existence or absence of the ultralight
dark matter halo.
- Short Baseline Neutrino Anomalies at Stopped Pion Experiments
2310.13194 [abs] [pdf]
[abstract]
by Iain A. Bisset, [and 3 more]Bhaskar Dutta, Wei-Chih Huang, and Louis E. Strigari [hide authors].
Stopped-pion experiments that measure coherent elastic neutrino-nucleus
scattering (CE$\nu$NS) are sensitive to sterile neutrinos via disappearance.
Using timing and energy spectra to perform flavor decomposition, we show that
the delayed electron neutrino component provides an independent test of
short-baseline anomalies that hint at $\sim$ eV-mass sterile neutrinos.
Dedicated experiments will be sensitive to nearly the entire sterile neutrino
parameter space consistent with short-baseline data.
- Study of non-standard interaction mediated by a scalar field at ESSnuSB
experiment
2310.10749 [abs] [pdf]
[abstract]
by ESSnuSB, [and 91 more]:, J. Aguilar, M. Anastasopoulos, E. Baussan, A. K. Bhattacharyya, A. Bignami, M. Blennow, M. Bogomilov, B. Bolling, E. Bouquerel, F. Bramati, A. Branca, W. Brorsson, I. Bustinduy, C. J. Carlile, J. Cederkall, T. W. Choi, S. Choubey, P. Christiansen, M. Collins, E. Cristaldo Morales, H. Danared, D. Dancila, J. P. A. M. de André, M. Dracos, I. Efthymiopoulos, T. Ekelöf, M. Eshraqi, G. Fanourakis, A. Farricker, E. Fasoula, T. Fukuda, N. Gazis, Th. Geralis, M. Ghosh, A. Giarnetti, G. Gokbulut, C. Hagner, L. Halić, V. T. Hariharan, K. E. Iversen, M. Jenssen, R. Johansson, E. Kasimi, A. Kayis Topaksu, B. Kildetof, B. Kliček, K. Kordas, A. Leisos, M. Lindroos, A. Longhin, C. Maiano, S. Marangoni, C. Marrelli, C. Martins, D. Meloni, M. Mezzetto, N. Milas, J. Muñoz, M. Oglakci, T. Ohlsson, M. Olvegård, M. Pari, D. Patrzalek, G. Petkov, Ch. Petridou, P. Poussot, A. Psallidas, F. Pupilli, D. Raikwal, D. Saiang, D. Sampsonidis, C. Schwab, F. Sordo, A. Sosa, G. Stavropoulos, M. Stipčević, R. Tarkeshian, F. Terranova, T. Tolba, E. Trachanas, R. Tsenov, A. Tsirigotis, S. E. Tzamarias, G. Vankova-Kirilova, N. Vassilopoulos, S. Vihonen, J. Wurtz, V. Zeter, O. Zormpa, and Y. Zou [hide authors].
In this paper we study non-standard interactions mediated by a scalar field
(SNSI) in the context of ESSnuSB experiment. In particular we study the
capability of ESSnuSB to put bounds on the SNSI parameters and also study the
impact of SNSI in the measurement of the leptonic CP phase $\delta_{\rm CP}$.
Existence of SNSI modifies the neutrino mass matrix and this modification can
be expressed in terms of three diagonal real parameters ($\eta_{ee}$,
$\eta_{\mu\mu}$ and $\eta_{\tau\tau}$) and three off-diagonal complex
parameters ($\eta_{e \mu}$, $\eta_{e\tau}$ and $\eta_{\mu\tau}$). Our study
shows that the upper bounds on the parameters $\eta_{\mu\mu}$,
$\eta_{\tau\tau}$ and $\eta_{\mu\tau}$ depend upon how $\Delta m^2_{31}$ is
minimized in the theory. However, this is not the case when one tries to
measure the impact of SNSI on $\delta_{\rm CP}$. Further, we show that the CP
sensitivity of ESSnuSB can be completely lost for certain values of $\eta_{ee}$
and $\eta_{\mu\tau}$ for which the appearance channel probability becomes
independent of $\delta_{\rm CP}$.
- Probing self-interacting sterile neutrino dark matter with the diffuse
supernova neutrino background
2310.07145 [abs] [pdf]
[abstract]
by A. Baha Balantekin, [and 3 more]George M. Fuller, Anupam Ray, and Anna M. Suliga [hide authors].
The neutrinos in the diffuse supernova neutrino background (DSNB) travel over
cosmological distances and this provides them with an excellent opportunity to
interact with dark relics. We show that a cosmologically-significant relic
population of keV-mass sterile neutrinos with strong self-interactions could
imprint their presence in the DSNB. The signatures of the self-interactions
would be ``dips" in the otherwise smooth DSNB spectrum. Upcoming large-scale
neutrino detectors, for example Hyper-Kamiokande, have a good chance of
detecting the DSNB and these dips. If no dips are detected, this method serves
as an independent constraint on the sterile neutrino self-interaction strength
and mixing with active neutrinos. We show that relic sterile neutrino
parameters that evade X-ray and structure bounds may nevertheless be testable
by future detectors like TRISTAN, but may also produce dips in the DSNB which
could be detectable. Such a detection would suggest the existence of a
cosmologically-significant, strongly self-interacting sterile neutrino
background, likely embedded in a richer dark sector.
- A tolerable candle: the low-$ν$ method with LHC neutrinos
2310.06520 [abs] [pdf]
[abstract]
by Callum Wilkinson and Alfonso Garcia Soto.
The Forward Physics Facility (FPF) plans to use neutrinos produced at the
Large Hadron Collider (LHC) to make a variety of measurements at previously
unexplored TeV energies. Its primary goals include precision measurements of
the neutrino cross section and using the measured neutrino flux both to uncover
information about far-forward hadron production and to search for various
beyond standard model scenarios. However, these goals have the potential to
conflict: extracting information about the flux or cross section relies upon an
assumption about the other. In this manuscript, we demonstrate that the FPF can
use the low-$\nu$ method -- a technique for constraining the flux shape by
isolating neutrino interactions with low energy transfer to the nucleus -- to
break this degeneracy. We show that the low-$\nu$ method is effective for
extracting the $\nu_{\mu}$ flux shape, in a model-independent way. We discuss
its application for extracting the $\bar{\nu}_{\mu}$ flux shape, but find that
this is significantly more model dependent. Finally, we explore the precision
to which the $\nu_{\mu}$ flux shape could be constrained at the FPF, for a
variety of proposed detector options. We find that the precision would be
sufficient to discriminate between various realistic flux models.
- Effects of Annihilation with Low-Energy Neutrinos on High-Energy
Neutrinos from Binary Neutron Star Mergers and Rare Core-Collapse Supernovae
2310.05137 [abs] [pdf]
[abstract]
by Gang Guo, Yong-Zhong Qian, and Meng-Ru Wu.
We explore the possibility that high-energy (HE) neutrinos produced from
choked jets can be annihilated with low-energy (LE) neutrinos emitted from the
accretion disk around a black hole in binary neutron star mergers and rare
core-collapse supernovae. For HE neutrinos produced close to the stellar center
($\lesssim 10^{9}-10^{12}$ cm), we find that the emerging all-flavor spectrum
for neutrinos of $E\gtrsim 0.1-1$ PeV could be modified by a factor $E^{-n}$
with $n\gtrsim 0.4-0.5$ under realistic conditions. Flavor evolution of LE
neutrinos does not affect this result but can change the emerging flavor
composition of HE neutrinos. As a consequence, the above annihilation effect
may need to be considered for HE neutrinos produced from choked jets at small
radii. We briefly discuss the annihilation effects for different HE neutrino
production models and point out that such effects could be tested through
precise measurements of the diffuse neutrino spectrum and flavor composition.
- Neutrino CP Measurement in the Presence of RG Running with Mismatched
Momentum Transfers
2310.04077 [abs] [pdf]
[abstract]
by Shao-Feng Ge, Chui-Fan Kong, and Pedro Pasquini.
The neutrino mixing parameters are expected to have RG running effect in the
presence of new physics. If the momentum transfers at production and detection
mismatch with each other, the oscillation probabilities are generally modified
and become dependent on not just the neutrino energy but also the momentum
transfer. Even in the limit of vanishing baseline, the transition probability
for the appearance channel is interestingly not zero. This would significantly
affect the sensitivity of the genuine leptonic Dirac CP phase. We further
explore the possibility of combing the long- and short-baseline neutrino
experiments to constrain such RG running effect for the purpose of guaranteeing
the CP measurement. To simulate the double dependence on the neutrino energy
and momentum transfer, we extend the usual GLoBES simulation of fixed baseline
experiments and use a two-dimensional $\chi^2$ analysis to obtain
sensitivities.
September 2023
- Constraining non-unitary neutrino mixing using matter effects in
atmospheric neutrinos at INO-ICAL
2309.16942 [abs] [pdf]
[abstract]
by Sadashiv Sahoo, [and 3 more]Sudipta Das, Anil Kumar, and Sanjib Kumar Agarwalla [hide authors].
The mass-induced neutrino oscillation is a well established phenomenon that
is based on the unitary mixing among three light active neutrinos. Remarkable
precision on neutrino mixing parameters over the last decade or so has opened
up the prospects for testing the possible non-unitarity of the standard 3$\nu$
mixing matrix, which may arise in the seesaw extensions of the Standard Model
due to the admixture of three light active neutrinos with heavy isosinglet
neutrinos. Because of this non-unitary neutrino mixing (NUNM), the oscillation
probabilities among the three active neutrinos would be altered as compared to
the probabilities obtained assuming a unitary 3$\nu$ mixing matrix. In such a
NUNM scenario, neutrinos can experience an additional matter effect due to the
neutral current interactions with the ambient neutrons. Atmospheric neutrinos
having access to a wide range of energies and baselines can experience a
significant modifications in Earth's matter effect due to NUNM. In this paper,
we study in detail how the NUNM parameter $\alpha_{32}$ affects the muon
neutrino and antineutrino survival probabilities in a different way. Then, we
place a comparable and complementary constraint on $\alpha_{32}$ in a model
independent fashion using the proposed 50 kt magnetized Iron Calorimeter (ICAL)
detector under the India-based Neutrino Observatory (INO) project, which can
efficiently detect the atmospheric $\nu_\mu$ and $\bar\nu_\mu$ separately in
the multi-GeV energy range. Further, we discuss the advantage of charge
identification capability of ICAL and the impact of uncertainties in
oscillation parameters while constraining $\alpha_{32}$. We also compare the
$\alpha_{32}$ sensitivity of ICAL with that of future long-baseline experiments
DUNE and T2HK in isolation and combination.
- DUNE potential as a New Physics probe
2309.15924 [abs] [pdf]
[abstract]
by Adriano Cherchiglia and Jose Santiago.
Neutrino experiments, in the next years, aim to determine with precision all
the six parameters of the three-neutrino standard paradigm. The complete
success of the experimental program is, nevertheless, attached to the
non-existence (or at least smallness) of Non-Standard Interactions (NSI). In
this work, anticipating the data taken from long-baseline neutrino experiments,
we map all the weakly coupled theories that could induce sizable NSI, with the
potential to be determined in these experiments, in particular DUNE. Once
present constraints from other experiments are taken into account, in
particular charged-lepton flavor violation, we find that only models containing
leptoquarks (scalar or vector) and/or neutral isosinglet vector bosons are
viable. We provide the explicit matching formulas connecting weakly coupled
models and NSI, both in propagation and production. Departing from the weakly
coupled completion with masses at TeV scale, we also provide a global fit on
all NSI for DUNE, finding that NSI smaller than $10^{-2}$ cannot be probed even
in the best-case scenario.
- Impact of scalar NSI on the neutrino mass ordering sensitivity at DUNE,
HK and KNO
2309.12249 [abs] [pdf]
[abstract]
by Arnab Sarker, [and 4 more]Abinash Medhi, Dharitree Bezboruah, Moon Moon Devi, and Debajyoti Dutta [hide authors].
The study of neutrino non-standard interactions (NSI) is a well-motivated
phenomenological scenario to explore new physics beyond the Standard Model. The
possible scalar coupling of neutrinos ($\nu$) with matter is one of such new
physics scenarios that appears as a sub-dominant effect that can impact the
$\nu$-oscillations in matter. The presence of scalar NSI introduces an
additional contribution directly to the $\nu$-mass matrix in the interaction
Hamiltonian and subsequently to the $\nu$-oscillations. This indicates that
scalar NSI may have a significant impact on measurements related to
$\nu$-oscillations e.g. leptonic CP phase $(\delta_{CP})$, $\theta_{23}$ octant
and neutrino mass ordering (MO). The linear scaling of the effects of scalar
NSI with matter density also motivates its exploration in long-baseline (LBL)
experiments. In this paper, we study the impact of a scalar-mediated NSI on the
MO sensitivity of DUNE, HK and HK+KNO, which are upcoming LBL experiments. We
study the impact on MO sensitivities at these experiments assuming that scalar
NSI parameters are present in nature and is known from other non-LBL
experiments. We observe that the presence of diagonal scalar NSI elements can
significantly affect the $\nu$-mass ordering sensitivities. We then also
combine the data from DUNE with HK and HK+KNO to explore possible synergy among
these experiments in a wider parameter space. We also observe a significant
enhancement in the MO sensitivities for the combined analysis.
- Neutrino Imaging of the Galactic Centre and Millisecond Pulsar
Population
2309.10493 [abs] [pdf]
[abstract]
by Paul C. W. Lai, [and 5 more]Matteo Agostini, Foteini Oikonomou, Beatrice Crudele, Ellis R. Owen, and Kinwah Wu [hide authors].
In this work, we consider the possible presence of a large population of
millisecond pulsars in the Galactic Centre. Their direct detection would be
challenging due to severe pulse broadening caused by scattering of radiation.
We propose a new method to constrain their population with neutrino imaging of
the Galactic Centre. Millisecond pulsars are proposed cosmic-ray accelerators.
The high-energy protons they produce will collide with the baryonic matter in
the central molecular zone to create charged and neutral pions that decay into
neutrinos and $\gamma$-rays, respectively. The specific neutrino and
$\gamma$-ray fluxes must be below their corresponding observed values, allowing
us to put a conservative upper limit on the millisecond pulsar population of
N_MSP < 10,000 within a galacto-centric radius of 20 pc. This upper limit is
sensitive to the proton acceleration efficiency of the pulsars, but is less
dependent on the particle injection spectral index and the choice of mass
tracers. The population will be better constrained when high resolution
neutrino observations of the Galactic Centre become available. The presence of
these millisecond pulsars can account for the $\gamma$-ray excess in the
Galactic Centre.
- Neutrinos from Earth-Bound Dark Matter Annihilation
2309.10032 [abs] [pdf]
[abstract]
by Maxim Pospelov and Anupam Ray.
A sub-component of dark matter with a short collision length compared to a
planetary size leads to efficient accumulation of dark matter in astrophysical
bodies. We analyze possible neutrino signals from the annihilation of such dark
matter and conclude that in the optically thick regime for dark matter capture,
the Earth provides the largest neutrino flux. Using the results of the existing
searches, we consider two scenarios for the neutrino flux, from stopped mesons
and prompt higher-energy neutrinos. In both cases we exclude some previously
unexplored parts of the parameter space (dark matter mass, its abundance, and
the scattering cross section on nuclei) by recasting the existing neutrino
searches.
- Detecting High-Energy Neutrinos from Galactic Supernovae with ATLAS
2309.09771 [abs] [pdf]
[abstract]
by Alex Y. Wen, [and 3 more]Carlos A. Argüelles, Ali Kheirandish, and Kohta Murase [hide authors].
We show that ATLAS, a collider detector, can measure the flux of high-energy
supernova neutrinos, which can be produced from days to months after the
explosion. Using Monte Carlo simulations for predicted fluxes, we find at most
$\mathcal{O}(0.1-1)$ starting events and $\mathcal{O}(10-100)$ throughgoing
events from a supernova 10 kpc away. Possible Galactic supernovae from
Betelgeuse and Eta Carinae are further analyzed as demonstrative examples. We
argue that even with limited statistics, ATLAS has the ability to discriminate
among flavors and between neutrinos and antineutrinos, making it an unique
neutrino observatory so far unmatched in this capability.
- Energy-dependent flavour ratios in neutrino telescopes from charm
2309.09139 [abs] [pdf]
[abstract]
by Atri Bhattacharya, [and 3 more]Rikard Enberg, Mary Hall Reno, and Ina Sarcevic [hide authors].
The origin of the observed diffuse neutrino flux is not yet known. Studies of
the relative flavour content of the neutrino flux detected at Earth can give
information on the production mechanisms at the sources and on flavour mixing,
complementary to measurements of the spectral index and normalisation. Here we
demonstrate the effects of neutrino fluxes with different spectral shapes and
different initial flavour compositions dominating at different energies, and we
study the sensitivity of future measurements with the IceCube Neutrino
Observatory. Where one kind of flux gives way to another, this shows up as a
non-trivial energy dependence in the flavour compositions. We explore this in
the context of slow-jet supernovae and magnetar-driven supernovae -- two
examples of astrophysical sources where charm production may be effective.
Using current best-fit neutrino mixing parameters and their projected 2040
uncertainties, we use event ratios of different event morphologies at IceCube
to illustrate the possibilities of distinguishing the energy dependence of
neutrino flavour ratios.
- HeLIOS: The Superfluid Helium Ultralight Dark Matter Detector
2309.07995 [abs] [pdf]
[abstract]
by M. Hirschel, [and 6 more]V. Vadakkumbatt, N. P. Baker, F. M. Schweizer, J. C. Sankey, S. Singh, and J. P. Davis [hide authors].
The absence of a breakthrough in directly observing dark matter (DM) through
prominent large-scale detectors motivates the development of novel tabletop
experiments probing more exotic regions of the parameter space. If DM contains
ultralight bosonic particles, they would behave as a classical wave and could
manifest through an oscillating force on baryonic matter that is coherent over
$\sim 10^6$ periods. Our Helium ultraLIght dark matter Optomechanical Sensor
(HeLIOS) uses the high-$Q$ acoustic modes of superfluid helium-4 to resonantly
amplify this signal. A superconducting re-entrant microwave cavity enables
sensitive optomechanical readout ultimately limited by thermal motion at
millikelvin temperatures. Pressurizing the helium allows for the unique
possibility of tuning the mechanical frequency to effectively broaden the DM
detection bandwidth. We demonstrate the working principle of our prototype
HeLIOS detector and show that future generations of HeLIOS could explore
unconstrained parameter space for both scalar and vector ultralight DM after
just an hour of integration time.
- Fast Exact Algorithm for Neutrino Oscillation in Constant Matter Density
2309.06900 [abs] [pdf]
[abstract]
by James Page.
A recently published method for solving the neutrino evolution equation with
constant matter density is further refined and used to lay out an exact
algorithm for computing oscillation probabilities, which is moderately faster
than previous methods when looping through neutrinos of different energies. In
particular, the three examples of $\overset{\scriptscriptstyle{(-)}}{\nu}_e$
survival, $\overset{\scriptscriptstyle{(-)}}{\nu}_\mu$ survival and
$\overset{\scriptscriptstyle{(-)}}{\nu}_e$ appearance probabilities are written
in terms of mixing angles, mass differences and matter electron density. A
program based on this new method is found to be roughly twice as fast as, and
in agreement with, the leading GLoBES package. Furthermore, the behaviour of
all relevant effective parameters is sketched out in terms of a range of
neutrino energies, or matter electron densities. For instance, the
$\overset{\scriptscriptstyle{(-)}}{\nu}_e$ survival probability in constant
matter density is found to have no dependence on the mixing angle $\theta_{23}$
or the CP-violating phase $\delta_{13}$.
- Search for Lorentz-violation through sidereal effect at NOνA
Experiment
2309.01756 [abs] [pdf]
[abstract]
by Shashank Mishra, [and 3 more]Saurabh Shukla, Lakhwinder Singh, and Venktesh Singh [hide authors].
Long-baseline neutrino oscillation experiments offer a unique laboratory to
test the fundamental Lorentz symmetry, which is heart of both the standard
model of particle and general relativity theory. Deviations from the standard
neutrino oscillation or the sidereal modulation in neutrino events will
smoking-gun experimental signature of Lorentz and CPT violation. In this study,
we investigate the impact of the sidereal effect on standard neutrino
oscillation measurements within the context of the NO{\nu}A experiment.
Additionally, we assess the sensitivity of the NO{\nu}A experiment to detect
Lorentz-violating interactions, taking into account the sidereal effect.
Furthermore, we highlight potential of the NO{\nu}A experiment to set the new
constraints on anisotropic Lorentz-violating parameters.
August 2023
- When a complementarity in the neutrino and the quark mixing meets a
parameter symmetry and its implications to the unitarity
2309.00132 [abs] [pdf]
[abstract]
by Jae Jun Kim.
We present a complementarity that addresses relationships among the
parameters in the neutrino and the quark mixing matrix, use it to estimate the
size of the uncertainty among the elements in the matrix and address its
implications to the unitarity of the quark mixing matrix and Wolfenstein
parameterization and the tension in the first row. First, we describe how a
complementarity with a phase being introduced as an extra parameter can be held
in the nine independent schemes of parameterizing the matrix introducing a
discrete parameter symmetry within a certain size of uncertainty and how it can
be related to a combination of sine functions. With that, for the first time,
we describe a method that we can use to constrain the size of the uncertainty
associated with the parameters, not the central values, complementing that
among the diagonal elements in the neutrino mixing matrix. Then we do the same
for the quark sector and discuss its implication in the relation to the size of
the uncertainty among the elements. Seeing that our estimation is larger than
that was reported by running the global fit in the quark sector, our result
could be an indication that we may need to be cautious when addressing the
tension in the first row of the matrix in the quark sector and when running
global fit to constrain the size of the uncertainty, where Wolfenstein
parameterization, one that is not unitarity guaranteed, is used, as opposed to
the combination of the three rotational matrix. Given that the size of the
uncertainty for the individual diagonal element in the second and the third
row, our result also could be an indication that we may need to wait until the
size of uncertainty for the second and the third row goes down further before
addressing the tension. It could be an opening of considering the possibility
of a mixing between the neutrino and the quark sector too.
- Neutrino anisotropy as a probe of extreme astrophysical accelerators
2308.16225 [abs] [pdf]
[abstract]
by Marco Stein Muzio and Noémie Globus.
We consider how the cutoff of the ultrahigh energy neutrino spectrum
introduces an effective neutrino horizon, allowing for future neutrino
detectors to measure an anisotropy in neutrino arrival directions driven by the
local large-scale structure. We show that measurement of the level of this
anisotropy along with features of the neutrino spectrum will allow for a
measurement of the evolution of ultrahigh energy neutrino sources, which are
expected to also be the sources of ultrahigh energy cosmic rays.
- Shedding light on neutrino self-interactions with solar antineutrino
searches
2308.15849 [abs] [pdf]
[abstract]
by Quan-feng Wu and Xun-Jie Xu.
Solar antineutrinos are absent in the standard solar model prediction.
Consequently, solar antineutrino searches emerge as a powerful tool to probe
new physics capable of converting neutrinos into antineutrinos. In this study,
we highlight that neutrino self-interactions, recently gaining considerable
attention due to their cosmological and astrophysical implications, can lead to
significant solar antineutrino production. We systematically explore various
types of four-fermion effective operators and light scalar mediators for
neutrino self-interactions. By estimating the energy spectra and event rates of
solar antineutrinos at prospective neutrino detectors such as JUNO,
Hyper-Kamiokande, and THEIA, we reveal that solar antineutrino searches can
impose stringent constraints on neutrino self-interactions and probe the
parameter space favored by the Hubble tension.
- Examining the sensitivity of FASER to Generalized Neutrino Interactions
2308.15630 [abs] [pdf]
[abstract]
by F. J. Escrihuela, [and 4 more]L. J. Flores, O. G. Miranda, Javier Rendón, and R. Sánchez-Vélez [hide authors].
We investigate the sensitivity of the FASER$\nu$ detector, a novel
experimental setup at the LHC, to probe and constrain generalized neutrino
interactions (GNI). Employing a comprehensive theoretical framework, we model
the effects of generalized neutrino interactions on neutrino-nucleon deep
inelastic scattering processes within the FASER$\nu$ detector. By considering
all the neutrino channels produced at the LHC, we perform a statistical
analysis to determine the sensitivity of FASER$\nu$ to constrain these
interactions. Our results demonstrate that FASER$\nu$ can place stringent
constraints on the GNI effective couplings. Additionally, we study the relation
between GNI and a minimal Leptoquark model where the SM is augmented by a
singlet Leptoquark with hypercharge $1/3$. We have found that the sensitivities
for various combinations of the Leptoquark Yukawa couplings are approximately
$\mathcal{O}(1)$, particularly when considering a Leptoquark mass in the TeV
range.
- Sensitivity of IceCube-Gen2 to measure flavor composition of
Astrophysical neutrinos
2308.15220 [abs] [pdf]
[abstract]
by Neha Lad.
The observation of an astrophysical neutrino flux in IceCube and its
detection capability to separate between the different neutrino flavors has led
IceCube to constraint the flavor content of this flux. IceCube-Gen2 is the
planned extension of the current IceCube detector, which will be about 8 times
larger than the current instrumented volume. In this work, we study the
sensitivity of IceCube-Gen2 to the astrophysical neutrino flavor composition
and investigate its tau neutrino identification capabilities. We apply the
IceCube analysis on a simulated IceCube-Gen2 dataset that mimics the High
Energy Starting Event (HESE) classification. Reconstructions are performed
using sensors that have 3 times higher quantum efficiency and isotropic angular
acceptance compared to the current IceCube optical modules. We present the
projected sensitivity for 10 years of data on constraining the flavor ratio of
the astrophysical neutrino flux at Earth by IceCube-Gen2.
- Octant Degeneracy and Plots of Parameter Degeneracy in Neutrino
Oscillations Revisited
2308.15071 [abs] [pdf]
[abstract]
by Sho Sugama and Osamu Yasuda.
The three kinds of parameter degeneracy in neutrino oscillation, the
intrinsic, sign and octant degeneracy, form an eight-fold degeneracy. The
nature of this eight-fold degeneracy can be visualized on the
($\sin^22\theta_{13}$, $1/\sin^2\theta_{23}$)-plane, through quadratic curves
defined by $P(\nu_\mu\to\nu_e)=$ const. and $P(\bar{\nu}_\mu\to\bar{\nu}_e)=$
const., along with a straight line $P(\nu_\mu\to\nu_\mu)=$ const. After
$\theta_{13}$ was determined by reactor neutrino experiments, the intrinsic
degeneracy in $\theta_{13}$ transforms into an alternative octant degeneracy in
$\theta_{23}$, which can potentially be resolved by incorporating the value of
$P(\nu_\mu\to\nu_\mu)$. In this paper, we analytically discuss whether this
octant parameter degeneracy is resolved or persists in the future long baseline
accelerator neutrino experiments, such as T2HK, DUNE, T2HKK and ESS$\nu$SB. It
is found that the energy spectra near the first oscillation maximum are
effective in resolving the octant degeneracy, whereas those near the second
oscillation maximum are not.
- Neutrino amplitude decomposition, $S$ matrix rephasing invariance, and
reparametrization symmetry
2308.14501 [abs] [pdf]
[abstract]
by Hisakazu Minakata.
The $S$ matrix rephasing invariance is one of the fundamental principles of
quantum mechanics that originates in its probabilistic interpretation. For a
given $S$ matrix which describes neutrino oscillation, one can define the two
different rephased amplitudes $S_{\alpha \beta}^{ \text{Reph-1} } \equiv e^{ i
(\lambda_{1} / 2E) x} S_{\alpha \beta}$ and $S_{\alpha \beta}^{ \text{Reph-2} }
\equiv e^{ i (\lambda_{2} / 2E) x} S_{\alpha \beta}$, which are physically
equivalent to each other, where $\lambda_{k} / 2E$ denotes the energy
eigenvalue of the $k$-th mass eigenstate. We point out that the transformation
of the reparametrization (Rep) symmetry obtained with ``Symmetry Finder'' maps
$S_{\alpha \beta}^{ \text{Reph-1} }$ to $S_{\alpha \beta}^{ \text{Reph-2} }$,
and vice versa, providing a local and manifest realization of the $S$ matrix
rephasing invariance by the Rep symmetry of the 1-2 state exchange type. It is
strongly indicative of quantum mechanical nature of the Rep symmetry. The
rephasing and Rep symmetry relation, though its all-order treatment remains
incomplete, is shown to imply absence of the pure 1-3 exchange symmetry in
Denton~{\it et al.}~perturbation theory. It then triggers a study of
convergence of perturbation series.
- Study of Scalar Non Standard Interaction at Protvino to Super-ORCA
experiment
2308.10789 [abs] [pdf]
[abstract]
by Dinesh Kumar Singha, [and 4 more]Rudra Majhi, Lipsarani Panda, Monojit Ghosh, and Rukmani Mohanta [hide authors].
In this paper we have studied the phenomenon of non-standard interaction
mediated by a scalar field (SNSI) in the context of P2SO experiment and
compared its sensitivity with DUNE. In particular, we have studied the
capability of these two experiments to put bounds on the diagonal SNSI
parameters i.e., $\eta_{ee}$, $\eta_{\mu\mu}$ and $\eta_{\tau\tau}$ and studied
the impact of these parameters on the determination of neutrino mass ordering,
octant of $\theta_{23}$ and CP violation (CPV). In our analysis we find that,
the parameter $\Delta m^2_{31}$ has a non-trivial role if one wants estimate
the bounds on $\eta_{\mu\mu}$ and $\eta_{\tau\tau}$ assuming SNSI does not
exist in nature. Our results show that sensitivity of P2SO and DUNE to
constraint $\eta_{\mu\mu}$ and $\eta_{\tau\tau}$ are similar whereas the
sensitivity of DUNE is slightly better for $\eta_{ee}$. We find that the mass
ordering and CPV sensitivities are mostly affected by $\eta_{ee}$ compared to
$\eta_{\mu \mu}$ and $\eta_{\tau \tau}$ if one assumes SNSI exists in nature.
On the other hand, octant sensitivity is mostly affected by $\eta_{\mu \mu}$
and $\eta_{\tau \tau}$. These sensitivities can be either higher or lower than
the standard three flavour scenario depending on the relative sign of the SNSI
parameters. Regarding the precision of atmospheric mixing parameters, we find
that the precision of $\theta_{23}$ deteriorates significantly in the presence
of $\eta_{\mu\mu}$ and $\eta_{\tau\tau}$.
- A Survey of Neutrino Flavor Models and the Neutrinoless Double Beta
Decay Funnel
2308.09737 [abs] [pdf]
[abstract]
by Peter B. Denton and Julia Gehrlein.
The neutrinoless double beta decay experimental effort continues to make
tremendous progress with hopes of covering the inverted neutrino mass hierarchy
in coming years and pushing from the quasi-degenerate hierarchy into the normal
hierarchy. As neutrino oscillation data is starting to suggest that the mass
ordering may be normal, we may well be faced with staring down the funnel of
death: a region of parameter space in the normal ordering where -- for a
particular cancellation among the absolute neutrino mass scale, the Majorana
phases, and the oscillation parameters -- the neutrinoless double beta decay
rate may be vanishingly small. To answer the question of whether this region of
parameter space is theoretically preferred, we survey five broad categories of
flavor model structures which make various different predictions for parameters
relevant for neutrinoless double beta decay to determine how likely it is that
the rate may be in this funnel region. We find that a non-negligible fraction
of predictions surveyed are at least partially in the funnel region. Our
results can guide model builders and experimentalists alike in focusing their
efforts on theoretically motivated regions of parameter space.
- Joint measurement of the ultra-high-energy neutrino spectrum and cross
section
2308.07709 [abs] [pdf]
[abstract]
by Victor B. Valera, Mauricio Bustamante, and Olga Mena.
Soon, a new generation of neutrino telescopes, presently under planning, will
target the discovery of ultra-high-energy (UHE) neutrinos of cosmic origin,
with energies higher than 100 PeV, that promise unique insight into
astrophysics and particle physics. Yet, predictions of the UHE neutrino flux
and interaction cross section -- whose measurement is co-dependent -- are laden
with significant uncertainty that, if unaddressed, could misrepresent the
capabilities to measure one or the other. To address this, we advocate for the
joint measurement of the UHE neutrino spectrum and neutrino-nucleon cross
section, including of their energy dependence, without assuming prior knowledge
of either. We illustrate our methods by adopting empirical parametrizations of
the neutrino spectrum, in forecasts geared to the planned radio array of the
IceCube-Gen2 neutrino telescope. We warn against using simple parametrizations
-- a simple power law or one augmented with an exponential cut-off -- that
might fail to capture features of the spectrum that are commonplace in the
predictions. We argue instead for the use of flexible parametrizations -- a
piecewise power law or an interpolating polynomial -- that ensure accuracy. We
report loose design targets for the detector energy and angular resolution that
are compatible with those under present consideration.
- Benefits of Looking for Coincident Events, Taus, and Muons with the
Askaryan Radio Array
2308.07401 [abs] [pdf]
[abstract]
by Abby Bishop, [and 3 more]Austin Cummings, Ryan Krebs, and William Luszczak [hide authors].
Ultra-High Energy (UHE) neutrinos over $10^{16}$ eV have yet to be observed
but the Askaryan Radio Array (ARA) is one in-ice neutrino observatory
attempting to make this discovery. In anticipation of a thorough
full-observatory and full-livetime neutrino search, we estimate how many
neutrino events can be detected accounting for secondary interactions, which
are typically ignored in UHE neutrino simulations. Using the NuLeptonSim and
PyREx simulation frameworks, we calculate the abundance and usefulness of
cascades viewed by multiple ARA stations and observations made of taus, muons,
and neutrinos generated during and after initial neutrino cascades. Analyses
that include these scenarios benefit from a considerable increase in effective
area at key ARA neutrino energies, one example being a 30% increase in ARA's
effective area when simulating taus and muons produced in $10^{19}$ eV neutrino
interactions. These analysis techniques could be utilized by other in-ice radio
neutrino observatories, as has been explored by NuRadioMC developers. Our
contribution showcases full simulation results of neutrinos with energies
$3\times10^{17}$ - $10^{21}$ eV and visualizations of interesting triggered
event topologies.
- From Dirac to Majorana: the Cosmic Neutrino Background capture rate in
the minimally extended Standard Model
2308.05147 [abs] [pdf]
[abstract]
by Yuber F. Perez-Gonzalez and Manibrata Sen.
We investigate the capture rate of the cosmic neutrino background on tritium
within the Standard Model, extended to incorporate three right-handed singlet
neutrinos with explicit lepton-number violation. We consider a scenario where
the $6 \times 6$ neutrino mixing matrix factorizes into three independent $2
\times 2$ pairs and analyze the states produced from weak interactions just
before neutrino decoupling. Taking into account the unrestricted Majorana mass
scale associated with lepton number violation, spanning from the Grand
Unification scale to Planck-suppressed values, we observe a gradual transition
in the capture rate from a purely Majorana neutrino to a purely (pseudo) Dirac
neutrino. We demonstrate that the capture rate is modified if the lightest
active neutrino is relativistic, and this can be used to constrain the tiniest
value of mass-squared difference $\sim 10^{-35}\,{\rm eV}^2$, between the
active-sterile pair, probed so far. Consequently, the cosmic neutrino capture
rate could become a promising probe for discerning the underlying mechanism
responsible for generating neutrino masses.
- Probing Earth's Missing Potassium using the Unique Antimatter Signature
of Geoneutrinos
2308.04154 [abs] [pdf]
[abstract]
by LiquidO Consortium, [and 79 more]:, A. Cabrera, M. Chen, F. Mantovani, A. Serafini, V. Strati, J. Apilluelo, L. Asquith, J. L. Beney, T. J. C. Bezerra, M. Bongrand, C. Bourgeois, D. Breton, M. Briere, J. Busto, A. Cadiou, E. Calvo, V. Chaumat, E. Chauveau, B. J. Cattermole, P. Chimenti, C. Delafosse, H. de Kerret, S. Dusini, A. Earle, C. Frigerio-Martins, J. Galán, J. A. García, R. Gazzini, A. Gibson-Foster, A. Gallas, C. Girard-Carillo, W. C. Griffith, F. Haddad, J. Hartnell, A. Hourlier, G. Hull, I. G. Irastorza, L. Koch, P. Laniéce, J. F. Le Du, C. Lefebvre, F. Lefevre, F. Legrand, P. Loaiza, J. A. Lock, G. Luzón, J. Maalmi, C. Marquet, M. Martínez, B. Mathon, L. Ménard, D. Navas-Nicolás, H. Nunokawa, J. P. Ochoa-Ricoux, M. Obolensky, C. Palomares, P. Pillot, J. C. C. Porter, M. S. Pravikoff, H. Ramarijaona, M. Roche, P. Rosier, B. Roskovec, M. L. Sarsa, S. Schoppmann, W. Shorrock, L. Simard, H. Th. J. Steiger, D. Stocco, J. S. Stutzmann, F. Suekane, A. Tunc, M. -A. Verdier, A. Verdugo, B. Viaud, S. M. Wakely, A. Weber, and F. Yermia [hide authors].
The formation of the Earth remains an epoch with mysterious puzzles extending
to our still incomplete understanding of the planet's potential origin and bulk
composition. Direct confirmation of the Earth's internal heat engine was
accomplished by the successful observation of geoneutrinos originating from
uranium (U) and thorium (Th) progenies, manifestations of the planet's natural
radioactivity dominated by potassium (40K) and the decay chains of uranium
(238U) and thorium (232Th). This radiogenic energy output is critical to
planetary dynamics and must be accurately measured for a complete understanding
of the overall heat budget and thermal history of the Earth. Detecting
geoneutrinos remains the only direct probe to do so and constitutes a
challenging objective in modern neutrino physics. In particular, the intriguing
potassium geoneutrinos have never been observed and thus far have been
considered impractical to measure. We propose here a novel approach for
potassium geoneutrino detection using the unique antimatter signature of
antineutrinos to reduce the otherwise overwhelming backgrounds to observing
this rarest signal. The proposed detection framework relies on the innovative
LiquidO detection technique to enable positron (e+) identification and
antineutrino interactions with ideal isotope targets identified here for the
first time. We also provide the complete experimental methodology to yield the
first potassium geoneutrino discovery.
- Solar neutrinos and $ν_2$ visible decays to $ν_1$
2308.03838 [abs] [pdf]
[abstract]
by André de Gouvêa, Jean Weill, and Manibrata Sen.
Experimental bounds on the neutrino lifetime depend on the nature of the
neutrinos and the details of the potentially new physics responsible for
neutrino decay. In the case where the decays involve active neutrinos in the
final state, the neutrino masses also qualitatively impact how these manifest
themselves experimentally. In order to further understand the impact of nonzero
neutrino masses, we explore how observations of solar neutrinos constrain a
very simple toy model. We assume that neutrinos are Dirac fermions and there is
a new massless scalar that couples to neutrinos such that a heavy neutrino -
$\nu_2$ with mass $m_2$ - can decay into a lighter neutrino - $\nu_1$ with mass
$m_1$ - and a massless scalar. We find that the constraints on the new physics
coupling depend, sometimes significantly, on the ratio of the
daughter-to-parent neutrino masses, and that, for large enough values of the
new physics coupling, the "dark side" of the solar neutrino parameter space -
$\sin^2\theta_{12}\sim 0.7$ - provides a reasonable fit to solar neutrino data.
Our results generalize to other neutrino-decay scenarios, including those that
mediate $\nu_2\to\nu_1\bar{\nu}_3\nu_3$ when the neutrino mass ordering is
inverted mass and $m_2>m_1\gg m_3$, the mass of $\nu_3$.
- Sensitivity of octant of $θ_{23}$, CP violation and mass hierarchy
in NO$ν$A with multinucleon and detector effects
2308.03702 [abs] [pdf]
[abstract]
by Paramita Deka and Kalpana Bora.
In this work, we investigate how multinucleon enhancement and RPA (Random
Phase Approximation) suppression can affect the measurement of three unknown
neutrino oscillation parameters - the CP-violating phase $\delta_{CP}$, the
octant of the atmospheric mixing angle $\theta_{23}$, and the determination of
the mass hierarchy, in the appearance channel of the NO$\nu$A experiment. We
include the presence of the detector effect as well in the analysis, which is
crucial for capturing realistic experimental scenarios. We also conducted a
comparison between the nuclear model Effective Spectral Function (calculated
within the RFG model) with and without Transverse Enhancement in terms of
sensitivity analysis. It is found that the analysis using our comprehensive
model QE(+RPA)+2p2h along with Effective Spectral Function+Transverse
Enhancement exhibits significantly enhanced sensitivity compared to the pure QE
interaction process, in all the cases.Also, the higher octant of $\theta_{23}$,
the lower half plane of $\delta_{CP}$, and the normal mass hierarchy
(HO-LHP-NH) exhibit improved sensitivity, enabling a more precise determination
of the corresponding parameters. Furthermore, it is also noted that improving
the performance of the detector also improves the results. Thus, including
multinucleon effects and improving detector efficiency have the potential to
enhance the capabilities of the NO$\nu$A (and other long baseline) experiment
in conducting precise parameter studies.
- Supernova Simulations Confront SN 1987A Neutrinos
2308.01403 [abs] [pdf]
[abstract]
by Damiano F. G. Fiorillo, [and 5 more]Malte Heinlein, Hans-Thomas Janka, Georg Raffelt, Edoardo Vitagliano, and Robert Bollig [hide authors].
We return to interpreting the historical SN~1987A neutrino data from a modern
perspective. To this end, we construct a suite of spherically symmetric
supernova models with the Prometheus-Vertex code, using four different
equations of state and five choices of final baryonic neutron-star (NS) mass in
the 1.36-1.93 M$_\odot$ range. Our models include muons and proto-neutron star
(PNS) convection by a mixing-length approximation. The time-integrated signals
of our 1.44 M$_\odot$ models agree reasonably well with the combined data of
the four relevant experiments, IMB, Kam-II, BUST, and LSD, but the
high-threshold IMB detector alone favors a NS mass of 1.7-1.8 M$_\odot$,
whereas Kam-II alone prefers a mass around 1.4 M$_\odot$. The cumulative energy
distributions in these two detectors are well matched by models for such NS
masses, and the previous tension between predicted mean neutrino energies and
the combined measurements is gone, with and without flavor swap. Generally, our
predicted signals do not strongly depend on assumptions about flavor mixing,
because the PNS flux spectra depend only weakly on antineutrino flavor. While
our models show compatibility with the events detected during the first
seconds, PNS convection and nucleon correlations in the neutrino opacities lead
to short PNS cooling times of 5-9 s, in conflict with the late event bunches in
Kam-II and BUST after 8-9 s, which are also difficult to explain by background.
Speculative interpretations include the onset of fallback of transiently
ejected material onto the NS, a late phase transition in the nuclear medium,
e.g., from hadronic to quark matter, or other effects that add to the standard
PNS cooling emission and either stretch the signal or provide a late source of
energy. More research, including systematic 3D simulations, is needed to assess
these open issues.
- Black Holes as Neutrino Factories
2308.00741 [abs] [pdf]
[abstract]
by Yifan Chen, Xiao Xue, and Vitor Cardoso.
Ultralight bosons near rotating black holes can grow significantly via
superradiant energy extraction, potentially reaching field values close to the
Planck scale, thereby turning black holes into effective transducers for these
fields. The interaction between a boson field and fermions can initiate a
parametric production of fermions, potentially halting the exponential growth
and leading to a saturated state of the boson cloud. This dynamic offers a
framework for establishing limits on boson-neutrino interactions, which have
traditionally been restricted by neutrino self-interaction considerations. At
the saturation phase, boson clouds have the capacity to propel neutrinos to
TeV-scale energies, generating fluxes that surpass atmospheric neutrino fluxes
from nearby black holes. This mechanism extends to dark sector fermions,
leading to the generation of boosted dark matter. These fluxes open novel
avenues for observation through high-energy neutrino detectors like IceCube, as
well as through dark matter direct detection, by directing observational
efforts towards targeted black holes.
July 2023
- From ray to spray: augmenting amplitudes and taming fast oscillations in
fully numerical neutrino codes
2308.00037 [abs] [pdf]
[abstract]
by Michele Maltoni.
In this note we describe how to complement the neutrino evolution matrix
calculated at a given energy and trajectory with additional information which
allows to reliably extrapolate it to nearby energies or trajectories without
repeating the full computation. Our method works for arbitrary matter density
profiles, can be applied to any propagation model described by an Hamiltonian,
and exactly guarantees the unitarity of the evolution matrix. As a
straightforward application, we show how to enhance the calculation of the
theoretical predictions for experimentally measured quantities, so that they
remain accurate even in the presence of fast neutrino oscillations.
Furthermore, the ability to "move around" a given energy and trajectory opens
the door to precise interpolation of the oscillation amplitudes within a grid
of tabulated values, with potential benefits for the computation speed of
Monte-Carlo codes. We also provide a set of examples to illustrate the most
prominent features of our approach.
- Recent neutrino oscillation result with the IceCube experiment
2307.15855 [abs] [pdf]
[abstract]
by Shiqi Yu and Jessie Micallef.
The IceCube South Pole Neutrino Observatory is a Cherenkov detector
instrumented in a cubic kilometer of ice at the South Pole. IceCube's primary
scientific goal is the detection of TeV neutrino emissions from astrophysical
sources. At the lower center of the IceCube array, there is a subdetector
called DeepCore, which has a denser configuration that makes it possible to
lower the energy threshold of IceCube and observe GeV-scale neutrinos, opening
the window to atmospheric neutrino oscillations studies. Advances in physics
sensitivity have recently been achieved by employing Convolutional Neural
Networks to reconstruct neutrino interactions in the DeepCore detector. In this
contribution, the recent IceCube result from the atmospheric muon neutrino
disappearance analysis using the CNN-reconstructed neutrino sample is presented
and compared to the existing worldwide measurements.
- A relook at the GZK Neutrino-Photon Connection: Impact of Extra-galactic
Radio Background & UHECR properties
2307.15667 [abs] [pdf]
[abstract]
by Sovan Chakraborty, Poonam Mehta, and Prantik Sarmah.
Ultra-high energy cosmic rays (UHECRs) beyond the Greisen-Zatsepin-Kuzmin
(GZK) cut-off provide us with a unique opportunity to understand the universe
at extreme energies. Secondary GZK photons and GZK neutrinos associated with
the same interaction are indeed interconnected and render access to
multi-messenger analysis of UHECRs. The GZK photon flux is heavily attenuated
due to the interaction with Cosmic Microwave Background (CMB) and the
Extra-galactic Radio Background (ERB). The present estimate of the ERB
comprising of several model uncertainties together with the ARCADE2 radio
results in large propagation uncertainties in the GZK photon flux. On the other
hand, the weakly interacting GZK neutrino flux is unaffected by these
propagation effects. In this work, we make an updated estimate of the GZK
photon and GZK neutrino fluxes considering a wide variation of both the
production and propagation properties of the UHECR like, the spectral index,
the cut-off energy of the primary spectrum, the distribution of sources and the
uncertainties in the ERB estimation. We explore the detection prospects of the
GZK fluxes with various present and upcoming UHECR and UHE neutrino detectors
such as Auger, TA, GRAND, ANITA, ARA, IceCube and IceCube-Gen2. The predicted
fluxes are found to be beyond the reach of the current detectors. In future,
proposed IceCube-Gen2, Auger upgrade and GRAND experiments will have the
sensitivity to the predicted GZK photon and GZK neutrino fluxes. Such detection
can put constraints on the UHECR source properties and the propagation effects
due to the ERB. We also propose an indirect limit on the GZK photon flux using
the neutrino-photon connection for any future detection of GZK neutrinos by the
IceCube-Gen2 detector. We find this limit to be consistent with our GZK flux
predictions.
- Ab initio calculations of neutrinoless $ββ$ decay refine
neutrino mass limits
2307.15156 [abs] [pdf]
[abstract]
by A. Belley, [and 3 more]T. Miyagi, S. R. Stroberg, and J. D. Holt [hide authors].
Neutrinos are perhaps the most elusive known particles in the universe. We
know they have some nonzero mass, but unlike all other particles, the absolute
scale remains unknown. In addition, their fundamental nature is uncertain; they
can either be their own antiparticles or exist as distinct neutrinos and
antineutrinos. The observation of the hypothetical process of neutrinoless
double-beta ($0\nu\beta\beta$) decay would at once resolve both questions,
while providing a strong lead in understanding the abundance of matter over
antimatter in our universe. In the scenario of light-neutrino exchange, the
decay rate is governed by, and thereby linked to the effective mass of the
neutrino via, the theoretical nuclear matrix element (NME). In order to extract
the neutrino mass, if a discovery is made, or to assess the discovery potential
of next-generation searches, it is essential to obtain accurate NMEs for all
isotopes of experimental interest. However, two of the most important cases,
$^{130}$Te and $^{136}$Xe, lie in the heavy region and have only been
accessible to phenomenological nuclear models. In this work we utilize powerful
advances in ab initio nuclear theory to compute NMEs from the underlying
nuclear and weak forces driving this decay, including the recently discovered
short-range component. We find that ab initio NMEs are generally smaller than
those from nuclear models, challenging the expected reach of future ton-scale
searches as well as claims to probe the inverted hierarchy of neutrino masses.
With this step, ab initio calculations with theoretical uncertainties are now
feasible for all isotopes relevant for next-generation $0\nu\beta\beta$ decay
experiments.
- Supernova Emission of Secretly Interacting Neutrino Fluid: Theoretical
Foundations
2307.15122 [abs] [pdf]
[abstract]
by Damiano F. G. Fiorillo, Georg Raffelt, and Edoardo Vitagliano.
Neutrino-neutrino scattering could have a large secret component that would
turn neutrinos within a supernova (SN) core into a self-coupled fluid. Neutrino
transport within the SN core, emission from its surface, expansion into space,
and the flux spectrum and time structure at Earth might all be affected. We
examine these questions from first principles. First, diffusive transport
differs only by a modified spectral average of the interaction rate. We next
study the fluid energy transfer between a hot and a cold blackbody surface in
plane-parallel and spherical geometry. The key element is the decoupling
process within the radiating bodies, which themselves are taken to be
isothermal. For a zero-temperature cold plate, mimicking radiation into free
space by the hot plate, the energy flux is 3--4\% smaller than the usual
Stefan-Boltzmann Law. The fluid energy density just outside the hot plate is
numerically 0.70 of the standard case, the outflow velocity is the speed of
sound $v_s=c/\sqrt{3}$, conspiring to a nearly unchanged energy flux. Our
results provide the crucial boundary condition for the expansion of the
self-interacting fluid into space, assuming an isothermal neutrino sphere. We
also derive a dynamical solution, assuming the emission suddenly begins at some
instant. A neutrino front expands in space with luminal speed, whereas the
outflow velocity at the radiating surface asymptotically approaches $v_s$ from
above. Asymptotically, one thus recovers the steady-state emission found in the
two-plate model. A sudden end to neutrino emission leads to a fireball with
constant thickness equal to the duration of neutrino emission.
- Large Neutrino Secret Interactions, Small Impact on Supernovae
2307.15115 [abs] [pdf]
[abstract]
by Damiano F. G. Fiorillo, Georg Raffelt, and Edoardo Vitagliano.
When hypothetical neutrino secret interactions ($\nu$SI) are large, they form
a fluid in a supernova (SN) core, flow out with sonic speed, and stream away as
a fireball. For the first time, we tackle the complete dynamical problem and
solve all steps, systematically using relativistic hydrodynamics. The impact on
SN physics and the neutrino signal is remarkably small. For complete
thermalization within the fireball, the observable spectrum changes in a way
that is independent of the coupling strength. One potentially large effect
beyond our study is quick deleptonization if $\nu$SI violate lepton number. By
present evidence, however, SN physics leaves open a large region in parameter
space, where laboratory searches and future high-energy neutrino telescopes
will probe $\nu$SI.
- Final results of Borexino on CNO solar neutrinos
2307.14636 [abs] [pdf]
[abstract]
by D. Basilico, [and 74 more]G. Bellini, J. Benziger, R. Biondi, B. Caccianiga, F. Calaprice, A. Caminata, A. Chepurnov, D. D'Angelo, A. Derbin, A. Di Giacinto, V. Di Marcello, X. F. Ding, A. Di Ludovico, L. Di Noto, I. Drachnev, D. Franco, C. Galbiati, C. Ghiano, M. Giammarchi, A. Goretti, M. Gromov, D. Guffanti, Aldo Ianni, Andrea Ianni, A. Jany, V. Kobychev, G. Korga, S. Kumaran, M. Laubenstein, E. Litvinovich, P. Lombardi, I. Lomskaya, L. Ludhova, I. Machulin, J. Martyn, E. Meroni, L. Miramonti, M. Misiaszek, V. Muratova, R. Nugmanov, L. Oberauer, V. Orekhov, F. Ortica, M. Pallavicini, L. Pelicci, Ö. Penek, L. Pietrofaccia, N. Pilipenko, A. Pocar, G. Raikov, M. T. Ranalli, G. Ranucci, A. Razeto, A. Re, N. Rossi, S. Schönert, D. Semenov, G. Settanta, M. Skorokhvatov, A. Singhal, O. Smirnov, A. Sotnikov, R. Tartaglia, G. Testera, E. Unzhakov, F. L. Villante, A. Vishneva, R. B. Vogelaar, F. von Feilitzsch, M. Wojcik, M. Wurm, S. Zavatarelli, K. Zuber, and G. Zuzel [hide authors].
We report the first measurement of CNO solar neutrinos by Borexino that uses
the Correlated Integrated Directionality (CID) method, exploiting the
sub-dominant Cherenkov light in the liquid scintillator detector. The
directional information of the solar origin of the neutrinos is preserved by
the fast Cherenkov photons from the neutrino scattered electrons, and is used
to discriminate between signal and background. The directional information is
independent from the spectral information on which the previous CNO solar
neutrino measurements by Borexino were based. While the CNO spectral analysis
could only be applied on the Phase-III dataset, the directional analysis can
use the complete Borexino data taking period from 2007 to 2021. The absence of
CNO neutrinos has been rejected with >5{\sigma} credible level using the
Bayesian statistics. The directional CNO measurement is obtained without an
external constraint on the $^{210}$Bi contamination of the liquid scintillator,
which was applied in the spectral analysis approach. The final and the most
precise CNO measurement of Borexino is then obtained by combining the new
CID-based CNO result with an improved spectral fit of the Phase-III dataset.
Including the statistical and the systematic errors, the extracted CNO
interaction rate is $R(\mathrm{CNO})=6.7^{+1.2}_{-0.8} \, \mathrm{cpd/100 \,
tonnes}$. Taking into account the neutrino flavor conversion, the resulting CNO
neutrino flux at Earth is $\Phi_\mathrm{CNO}=6.7 ^{+1.2}_{-0.8} \times 10^8 \,
\mathrm{cm^{-2} s^{-1}}$, in agreement with the high metallicity Standard Solar
Models. The results described in this work reinforce the role of the event
directional information in large-scale liquid scintillator detectors and open
up new avenues for the next-generation liquid scintillator or hybrid neutrino
experiments.
- Identifying Spin Properties of Evaporating Black Holes through
Asymmetric Neutrino and Photon Emission
2307.14408 [abs] [pdf]
[abstract]
by Yuber F. Perez-Gonzalez.
Kerr black holes radiate neutrinos in an asymmetric pattern, preferentially
in the lower hemisphere relative to the black hole's rotation axis, while
antineutrinos are predominantly produced in the upper hemisphere. Leveraging
this asymmetric emission, we explore the potential of high-energy, $E_\nu
\gtrsim 1$ TeV, neutrino and antineutrino detection to reveal crucial
characteristics of an evaporating primordial black hole at the time of its
burst when observed near Earth. We improve upon previous calculations by
carefully accounting for the non-isotropic particle emission, as Earth occupies
a privileged angle relative to the black hole's rotation axis. Additionally, we
investigate the angular dependence of primary and secondary photon spectra and
assess the evaporating black hole's time evolution during the final explosive
stages of its lifetime. Since photon events outnumber neutrinos by about three
orders of magnitude, we find that a neutrino measurement can aid in identifying
the initial angular momentum and the black hole hemisphere facing Earth only
for evaporating black holes within our solar system, at distances $\lesssim
10^{-4}$ pc, and observed during the final 100 s of their lifetime.
- Search for the Migdal effect in liquid xenon with keV-level nuclear
recoils
2307.12952 [abs] [pdf]
[abstract]
by Jingke Xu, [and 13 more]Duncan Adams, Brian Lenardo, Teal Pershing, Rachel Mannino, Ethan Bernard, James Kingston, Eli Mizrachi, Junsong Lin, Rouven Essig, Vladimir Mozin, Phil Kerr, Adam Bernstein, and Mani Tripathi [hide authors].
The Migdal effect predicts that a nuclear recoil interaction can be
accompanied by atomic ionization, allowing many dark matter direct detection
experiments to gain sensitivity to sub-GeV masses. We report the first direct
search for the Migdal effect for M- and L-shell electrons in liquid xenon using
7.0$\pm$1.6 keV nuclear recoils produced by tagged neutron scatters. Despite an
observed background rate lower than that of expected signals in the region of
interest, we do not observe a signal consistent with predictions. We discuss
possible explanations, including inaccurate predictions for either the Migdal
rate or the signal response in liquid xenon. We comment on the implications for
direct dark-matter searches and future Migdal characterization efforts.
- On the impact of the Migdal effect in reactor CE$ν$NS experiments
2307.12911 [abs] [pdf]
[abstract]
by M. Atzori Corona, [and 4 more]M. Cadeddu, N. Cargioli, F. Dordei, and C. Giunti [hide authors].
The search for coherent elastic neutrino nucleus scattering (CE$\nu$NS) using
reactor antineutrinos represents a formidable experimental challenge, recently
boosted by the observation of such a process at the Dresden-II reactor site
using a germanium detector. This observation relies on an unexpected
enhancement at low energies of the measured quenching factor with respect to
the theoretical Lindhard model prediction, which implies an extra observable
ionization signal produced after the nuclear recoil. A possible explanation for
this additional contribution could be provided by the so-called Migdal effect,
which however has never been observed. Here, we study in detail the impact of
the Migdal contribution to the standard CE$\nu$NS signal calculated with the
Lindhard quenching factor, finding that the former is completely negligible for
observed energies below $\sim 0.3\,\mathrm{keV}$ where the signal is
detectable, and thus unable to provide any contribution to CE$\nu$NS searches
in this energy regime. To this purpose, we compare different formalisms used to
describe the Migdal effect that intriguingly show a perfect agreement, making
our findings robust.
- Probing mass orderings in presence of a very light sterile neutrino in a
liquid argon detector
2307.12885 [abs] [pdf]
[abstract]
by Animesh Chatterjee, Srubabati Goswami, and Supriya Pan.
Results from experiments like LSND and MiniBooNE hint towards the possible
presence of an extra eV scale sterile neutrino. The addition of such a neutrino
will significantly impact the standard three flavour neutrino oscillations. In
particular, it can give rise to additional degeneracies due to additional
sterile parameters. For an eV scale sterile neutrino, the cosmological
constraints dictate that the sterile state is heavier than the three active
states. However, for lower masses of sterile neutrinos, it can be lighter than
one and/or more of the three states. In such cases, the mass ordering of the
sterile neutrinos also becomes unknown along with the mass ordering of the
active states. In this paper, we explore the mass ordering sensitivity in the
presence of a sterile neutrino assuming the mass squared difference
$|\Delta_{41}|$ to be in the range $10^{-4} - 1$ eV$^2$. We study (i) how the
ordering of the active states, i.e. the determination of the sign of
$\Delta_{31}$ gets affected by the presence of a sterile neutrino in the above
mass range, (ii) the possible determination of the sign of $\Delta_{41}$ for
$\Delta_{41}$ in the range $10^{-4} - 0.1$ eV$^2$. This analysis is done in the
context of a liquid argon detector using both beam neutrinos traveling a
distance of 1300 km and atmospheric neutrinos which propagates through a
distance ranging from 10 - 10000 km allowing resonant matter effects. Apart
from presenting separate results from these sources, we also do a combined
study and probe the synergy between these two in giving an enhanced
sensitivity.
- Exploring Solar Neutrino Oscillation Parameters with LSC at Yemilab and
JUNO
2307.11582 [abs] [pdf]
[abstract]
by Pouya Bakhti, [and 3 more]Meshkat Rajaee, Seon-Hee Seo, and Seodong Shin [hide authors].
We investigate the sensitivities of the liquid scintillator counter (LSC) at
Yemilab and JUNO to solar neutrino oscillation parameters, focusing on
$\theta_{12}$ and $\Delta m^2_{21}$. We compare the potential of JUNO with LSC
at Yemilab utilizing both reactor and solar data in determining those
parameters. We find that the solar neutrino data of LSC at Yemilab is highly
sensitive to $\theta_{12}$ enabling its determination with exceptional
precision. Our study also reveals that if $\Delta m^2_{21}$ is larger, with a
value close to the best fit value of KamLAND, JUNO reactor data will have about
two times better precision than the reactor LSC at Yemilab. On the other hand,
if $\Delta m^2_{21}$ is smaller and closer to the best fit value of solar
neutrino experiments, the precision of the reactor LSC at Yemilab will be
better than JUNO.
- A $ν$ window onto leptoquarks?
2307.11152 [abs] [pdf]
[abstract]
by Matthew Kirk, Shohei Okawa, and Keyun Wu.
Upcoming neutrino telescopes promise a new window onto the interactions of
neutrinos with matter at ultrahigh energies ($E_\nu = 10^7$-$10^{10}$ GeV), and
the possibility to detect deviations from the Standard Model predictions. In
this paper, we update previous predictions for the enhancement of the
neutrino-nucleon cross-section for motivated leptoquark models and show the
latest neutrino physics bound, as well as analyse the latest LHC pair
production and Drell-Yan data, and flavour constraints (some of which were
previously missed). We find that, despite the next generation of neutrino
experiments probing the highest energies, they will not be enough to be
competitive with collider searches.
- Shedding light on the $Δm^2_{21}$ tension with supernova neutrinos
2307.09509 [abs] [pdf]
[abstract]
by Rasmi Hajjar, Sergio Palomares-Ruiz, and Olga Mena.
One long-standing tension in the determination of neutrino parameters is the
mismatched value of the solar mass square difference, $\Delta m_{21}^2$,
measured by different experiments: the reactor antineutrino experiment KamLAND
finds a best fit larger than the one obtained with solar neutrino data. Even if
the current tension is mild ($\sim 1.5\sigma$), it is timely to explore if
independent measurements could help in either closing or reassessing this
issue. In this regard, we explore how a future supernova burst in our galaxy
could be used to determine $\Delta m_{21}^2$ at the future Hyper-Kamiokande
detector, and how this could contribute to the current situation. We study
Earth matter effects for different models of supernova neutrino spectra and
supernova orientations. We find that, if supernova neutrino data prefers the
KamLAND best fit for $\Delta m_{21}^2$, an uncertainty similar to the current
KamLAND one could be achieved. On the contrary, if it prefers the solar
neutrino data best fit, the current tension with KamLAND results could grow to
a significance larger than $5\sigma$. Furthermore, supernova neutrinos could
significantly contribute to reducing the uncertainty on $\sin^2\theta_{12}$.
- Neutrino Signatures of One Hundred 2D Axisymmetric Core-Collapse
Supernova Simulations
2307.08735 [abs] [pdf]
[abstract]
by David Vartanyan and Adam Burrows.
We present in this paper a public data release of an unprecedentedly-large
set of core-collapse supernova (CCSN) neutrino emission models, comprising one
hundred detailed 2D-axisymmetric radiation-hydrodynamic simulations evolved out
to as late as ~5 seconds post-bounce and spanning a extensive range of
massive-star progenitors. The motivation for this paper is to provide a
physically and numerically uniform benchmark dataset to the broader neutrino
detection community to help it characterize and optimize subsurface facilities
for what is likely to be a once-in-a-lifetime galactic supernova burst event.
With this release we hope to 1) help the international experiment and modeling
communities more efficiently optimize the retrieval of physical information
about the next galactic core-collapse supernova, 2) facilitate the better
understanding of core-collapse theory and modeling among interested
experimentalists, and 3) help further integrate the broader supernova neutrino
community.
- Gauging the cosmic ray muon puzzle with the Forward Physics Facility
2307.08634 [abs] [pdf]
[abstract]
by Sergio J. Sciutto, [and 4 more]Luis A. Anchordoqui, Carlos Garcia Canal, Felix Kling, and Jorge F. Soriano [hide authors].
We investigate the observed muon deficit in air shower simulations when
compared to ultrahigh-energy cosmic ray (UHECR) data. Gleaned from the observed
enhancement of strangeness production in ALICE data, the associated $\pi
\leftrightarrow K$ swap is taken as a cornerstone to resolve the muon puzzle
via its corresponding impact on the shower evolution. We develop a
phenomenological model in terms of the $\pi \leftrightarrow K$ swapping
probability $F_s$. We provide a parametrization of $F_s (E^{\rm (proj)}, \eta)$
that can accommodate the UHECR data, where $E^{\rm (proj)}$ is the projectile
energy and $\eta$ the pseudorapidity. We also explore a future game plan for
model improvement using the colossal amount of data to be collected by LHC
neutrino detectors at the Forward Physics Facility (FPF). We calculate the
corresponding sensitivity to $F_s$ and show that the FPF experiments will be
able to probe the model phase space.
- New Measurements of $^{71}$Ge Decay: Impact on the Gallium Anomaly
2307.05353 [abs] [pdf]
[abstract]
by J. I. Collar and S. G. Yoon.
A dedicated high-statistics measurement of the $^{71}$Ge half-life is found
to be in accurate agreement with an accepted value of 11.43$\pm$0.03 d,
eliminating a recently proposed route to bypass the "gallium anomaly" affecting
several neutrino experiments. Our data also severely constrain the possibility
of $^{71}$Ge decay to low-energy excited levels of the $^{71}$Ga daughter
nucleus as a solution to this puzzle. Additional unpublished measurements of
this decay are discussed. Following the incorporation of this new information,
the gallium anomaly survives with high statistical significance.
- Scalar NSI: A unique tool for constraining absolute neutrino masses via
$ν$-oscillations
2307.05348 [abs] [pdf]
[abstract]
by Abinash Medhi, Arnab Sarker, and Moon Moon Devi.
In the standard interaction scenario, a direct measurement of absolute
neutrino masses via neutrino oscillations is not feasible, as the oscillations
depend only on the mass-squared differences. However, the presence of scalar
non-standard interactions can introduce sub-dominant terms in the oscillation
Hamiltonian that can directly affect the neutrino mass matrix and thereby
making scalar NSI a unique tool for neutrino mass measurements. In this work,
for the first time, we constrain the absolute masses of neutrinos by probing
scalar NSI. We show that a bound on the lightest neutrino mass can be induced
in the presence of scalar NSI at DUNE. We find that the lightest neutrino mass
can be best constrained with $\eta_{\tau\tau}$ and $\eta_{\mu\mu}$ at $2\sigma$
C.L. for normal and inverted hierarchy respectively. This study suggests that
scalar NSI can serve as an interesting avenue to constrain the absolute
neutrino masses in long-baseline neutrino experiments via neutrino
oscillations.
- Pulsar kicks in ultralight dark matter background induced by neutrino
oscillation
2307.05229 [abs] [pdf]
[abstract]
by Geatano Lambiase and Tanmay Kumar Poddar.
The interaction of neutrinos with ultralight scalar and vector dark matter
backgrounds induce a modification of the neutrino dispersion relation. The
effects of this modification are reviewed in the framework of asymmetric
emission of neutrinos from the supernova core, and, in turn, of pulsar kicks.
We consider the neutrino oscillations, focusing in particular to active-sterile
conversion. The ultralight dark matter induced neutrino dispersion relation
contains a term of the form $\delta {\bf \Omega}\cdot \hat{{\bf{p}}}$, where
$\delta {\bf \Omega}$ is related to the ultralight dark matter field and
$\hat{{\bf p}}$ is the unit vector along the direction of neutrino momentum.
The relative orientation of ${\bf p}$ with respect to $\delta {\bf \Omega}$
affects the mechanism for the generation of the observed pulsar velocities. We
obtain the resonance condition for the active-sterile neutrino oscillation in
ultralight dark matter background and calculate the star parameters in the
resonance surface so that both ultralight scalar and vector dark matter
backgrounds can explain the observed pulsar kicks. The asymmetric emission of
neutrinos in presence of ultralight dark matter background results
gravitational memory signal which can be probed from the gravitational wave
detectors. We also establish a connection between the ultralight dark matter
parameters and the standard model extension parameter.
- The Mikheyev-Smirnov-Wolfenstein Matter Potential at the One-loop Level
in the Standard Model
2307.04685 [abs] [pdf]
[abstract]
by Jihong Huang and Shun Zhou.
When neutrinos are propagating in ordinary matter, their coherent forward
scattering off background particles results in the so-called
Mikheyev-Smirnov-Wolfenstein (MSW) matter potential, which plays an important
role in neutrino flavor conversions. In this paper, we present a complete
one-loop calculation of the MSW matter potential in the Standard Model (SM).
First, we carry out the one-loop renormalization of the SM in the on-shell
scheme, where the electromagnetic fine-structure constant $\alpha$, the weak
gauge-boson masses $m^{}_W$ and $m^{}_Z$, the Higgs-boson mass $m^{}_h$ and the
fermion masses $m^{}_f$ are chosen as input parameters. Then, the finite
corrections to the scattering amplitudes of neutrinos with the electrons and
quarks are calculated, and the one-loop MSW matter potentials are derived.
Adopting the latest values of all physical parameters, we find that the
relative size of one-loop correction to the charged-current matter potential of
electron-type neutrinos or antineutrinos turns out to be $6\%$, whereas that to
the neutral-current matter potential of all-flavor neutrinos or antineutrinos
can be as large as $8\%$. The calculations are also performed in the
$\overline{\rm MS}$ scheme and compared with previous results in the
literature.
- Where shadows lie: reconstruction of anisotropies in the neutrino sky
2307.03191 [abs] [pdf]
[abstract]
by Willem Elbers, [and 7 more]Carlos S. Frenk, Adrian Jenkins, Baojiu Li, Silvia Pascoli, Jens Jasche, Guilhem Lavaux, and Volker Springel [hide authors].
The Cosmic Neutrino Background (CNB) encodes a wealth of information, but has
not yet been observed directly. To determine the prospects of detection and to
study its information content, we reconstruct the phase-space distribution of
local relic neutrinos from the three-dimensional distribution of matter within
200 Mpc/h of the Milky Way. Our analysis relies on constrained realization
simulations and forward modelling of the 2M++ galaxy catalogue. We find that
the angular distribution of neutrinos is anti-correlated with the projected
matter density, due to the capture and deflection of neutrinos by massive
structures along the line of sight. Of relevance to tritium capture
experiments, we find that the gravitational clustering effect of the
large-scale structure on the local number density of neutrinos is more
important than that of the Milky Way for neutrino masses less than 0.1 eV.
Nevertheless, we predict that the density of relic neutrinos is close to the
cosmic average, with a suppression or enhancement over the mean of (-0.3%, +7%,
+27%) for masses of (0.01, 0.05, 0.1) eV. This implies no more than a marginal
increase in the event rate for tritium capture experiments like PTOLEMY. We
also predict that the CNB and CMB rest frames coincide for 0.01 eV neutrinos,
but that neutrino velocities are significantly perturbed for masses larger than
0.05 eV. Regardless of mass, we find that the angle between the neutrino dipole
and the ecliptic plane is small, implying a near-maximal annual modulation in
the bulk velocity. Along with this paper, we publicly release our simulation
data, comprising more than 100 simulations for six different neutrino masses.
- Constraints on Neutrino Self-Interactions from IceCube Observation of
NGC 1068
2307.02361 [abs] [pdf]
[abstract]
by Jeffrey M. Hyde.
The active galaxy NGC 1068 was recently identified by the IceCube neutrino
observatory as the first known steady-state, extragalactic neutrino point
source, associated with about 79 events over ten years. We use the IceCube data
to place limits on possible neutrino self-interactions mediated by scalar
particles with mass between 1 - 10 MeV. We find that constraints on
flavor-specific $\nu_{\tau}$ self-interactions with low mediator masses are
comparable to constraints derived from the diffuse high-energy neutrino flux at
low energies, while constraints on flavor-universal self-interactions are less
restrictive than current bounds.
June 2023
- Neutrino winds on the sky
2307.00049 [abs] [pdf]
[abstract]
by Caio Nascimento and Marilena Loverde.
We develop a first-principles formalism to compute the distortion to the
relic neutrino density field caused by the peculiar motions of large-scale
structures. This distortion slows halos down due to dynamical friction, causes
a local anisotropy in the neutrino-CDM cross-correlation, and reduces the
global cross-correlation between neutrinos and CDM. The local anisotropy in the
neutrino-CDM cross-spectrum is imprinted in the three point cross-correlations
of matter and galaxies, or the bispectrum in Fourier space, producing a signal
peaking at squeezed triangle configurations. This bispectrum signature of
neutrino masses is not limited by cosmic variance or potential inaccuracies in
the modeling of complicated nonlinear and galaxy formation physics, and it is
not degenerate with the optical depth to reionization. We show that future
surveys have the potential to detect the distortion bispectrum.
- Galactic Diffuse Neutrino Emission from Sources beyond the Discovery
Horizon
2306.17285 [abs] [pdf]
[abstract]
by Antonio Ambrosone, [and 3 more]Kathrine Mørch Groth, Enrico Peretti, and Markus Ahlers [hide authors].
The IceCube Neutrino Observatory has recently reported strong evidence for
neutrino emission from the Galactic plane. The signal is consistent with model
predictions of diffuse emission from cosmic ray propagation in the interstellar
medium. However, due to IceCube's limited potential of identifying individual
neutrino sources, it is also feasible that unresolved Galactic sources could
contribute to the observation. We investigate the contribution of this
quasi-diffuse emission and show that the observed Galactic diffuse flux at
100~TeV could be dominated by hard emission of unresolved sources. Particularly
interesting candidate sources are young massive stellar clusters that have been
considered as cosmic-ray PeVatrons. We examine whether this hypothesis can be
tested by the upcoming KM3NeT detector or the planned future facility
IceCube-Gen2 with about five times the sensitivity of IceCube.
- Milky Way as a Neutrino Desert: Implications of the IceCube Galactic
Diffuse Neutrino Emission
2306.17275 [abs] [pdf]
[abstract]
by Ke Fang, John S. Gallagher, and Francis Halzen.
The Galactic diffuse emission (GDE) is formed when cosmic rays leave the
sources where they were accelerated, diffusively propagate in the Galactic
magnetic field, and interact with the interstellar medium and interstellar
radiation field. GDE in $\gamma$-ray (GDE-$\gamma$) has been observed up to
sub-PeV energies, though its origin may be explained by either cosmic-ray
nuclei or electrons. We show that the $\gamma$-rays accompanying the
high-energy neutrinos recently observed by the IceCube Observatory from the
Galactic plane have a flux that is consistent with the GDE-$\gamma$ observed by
the Fermi-LAT and Tibet AS$\gamma$ experiments around 1 TeV and 0.5 PeV,
respectively. The consistency suggests that the diffuse $\gamma$-ray emission
above $\sim$1 TeV could be dominated by hadronuclear interactions, though
partial leptonic contribution cannot be excluded. Moreover, by comparing the
fluxes of the Galactic and extragalactic diffuse emission backgrounds, we find
that the neutrino luminosity of the Milky Way is one to two orders of magnitude
lower than the average of distant galaxies. This implies that our Galaxy has
not hosted the type of neutrino emitters that dominates the isotropic neutrino
background in the past few million years.
- A Pythagoras-like theorem for CP violation in neutrino oscillations
2306.16231 [abs] [pdf]
[abstract]
by Shu Luo and Zhi-zhong Xing.
The probabilities of $\nu^{}_{\mu} \to \nu^{}_{e}$ and
$\overline{\nu}^{}_{\mu} \to \overline{\nu}^{}_{e}$ oscillations in vacuum are
determined by the CP-conserving flavor mixing factors ${\cal R}^{}_{ij} \equiv
{\rm Re} (U^{}_{\mu i} U^{}_{e j} U^{*}_{\mu j} U^{*}_{e i})$ and the universal
Jarlskog invariant of CP violation ${\cal J}^{}_{\nu} \equiv (-1)^{i+j} \; {\rm
Im} (U^{}_{\mu i} U^{}_{e j} U^{*}_{\mu j} U^{*}_{e i})$ (for $i, j = 1, 2, 3$
and $i < j$), where $U$ is the $3\times 3$ Pontecorvo-Maki-Nakagawa-Sakata
neutrino mixing matrix. We show that ${\cal J}^{2}_{\nu} = {\cal R}^{}_{12}
{\cal R}^{}_{13} + {\cal R}^{}_{12} {\cal R}^{}_{23} + {\cal R}^{}_{13} {\cal
R}^{}_{23}$ holds as a natural consequence of the unitarity of $U$. This
Pythagoras-like relation may provide a novel cross-check of the result of
${\cal J}^{}_{\nu}$ that will be directly measured in the next-generation
long-baseline neutrino oscillation experiments. Indirect non-unitarity effects
and terrestrial matter effects on ${\cal J}^{}_{\nu}$ and ${\cal R}^{}_{ij}$
are also discussed.
- Pion decay constraints on exotic 17 MeV vector bosons
2306.15077 [abs] [pdf]
[abstract]
by Matheus Hostert and Maxim Pospelov.
We derive constraints on the couplings of light vector particles to all
first-generation Standard Model fermions using leptonic decays of the charged
pion, $\pi^+\to e^+ \nu_e X_\mu$. In models where the net charge to which
$X_\mu$ couples is not conserved, no lepton helicity flip is required for the
decay to happen, enhancing the decay rate by factors of
${O}(m_\pi^4/m_e^2m_X^2)$. A past search at the SINDRUM-I spectrometer severely
constrains this possibility. In the context of the hypothesized $17$ MeV
particle proposed to explain anomalous $^8$Be, $^4$He, and $^{12}$C nuclear
transitions claimed by the ATOMKI experiment, this limit rules out vector-boson
explanations and poses strong limits on axial-vector ones.
- Neutrino oscillation bounds on quantum decoherence
2306.14699 [abs] [pdf]
[abstract]
by Valentina De Romeri, [and 3 more]Carlo Giunti, Thomas Stuttard, and Christoph A. Ternes [hide authors].
We consider quantum-decoherence effects in neutrino oscillation data. Working
in the open quantum system framework we adopt a phenomenological approach that
allows to parameterize the energy dependence of the decoherence effects. We
consider several phenomenological models. We analyze data from the reactor
experiments RENO, Daya Bay and KamLAND and from the accelerator experiments
NOvA, MINOS/MINOS+ and T2K. We obtain updated constraints on the decoherence
parameters quantifying the strength of damping effects, which can be as low as
$\Gamma_{ij} \lesssim 8 \times 10^{-27}$ GeV at 90% confidence level in some
cases. We also present sensitivities for the future facilities DUNE and JUNO.
- Distinctive nuclear signatures of low-energy atmospheric neutrinos
2306.11090 [abs] [pdf]
[abstract]
by Anna M. Suliga and John F. Beacom.
New probes of neutrino mixing are needed to advance precision studies. One
promising direction is via the detection of low-energy atmospheric neutrinos
(below a few hundred MeV), to which a variety of near-term experiments will
have much-improved sensitivity. Here we focus on probing these neutrinos
through distinctive nuclear signatures of exclusive neutrino-carbon
interactions -- those that lead to detectable nuclear-decay signals with low
backgrounds -- in both neutral-current and charged-current channels. The
neutral-current signature is a line at 15.11 MeV and the charged-current
signatures are two- or three-fold coincidences with delayed decays. We
calculate the prospects for identifying such events in the Jiangmen Underground
Neutrino Observatory (JUNO), a large-scale liquid-scintillator detector. A
five-year exposure would yield about 16 neutral-current events (all flavors)
and about 16 charged-current events (mostly from $\nu_e + \bar{\nu}_e$, with
some from $\nu_\mu + \bar{\nu}_\mu$), and thus roughly 25\% uncertainties on
each of their rates. Our results show the potential of JUNO to make the first
identified measurement of sub-100 MeV atmospheric neutrinos. They also are a
step towards multi-detector studies of low-energy atmospheric neutrinos, with
the goal of identifying additional distinctive nuclear signatures for carbon
and other targets.
- Probing general $U(1)'$ models with non-universal lepton charges at
FASER/FASER2, COHERENT and long-baseline oscillation experiments
2306.09569 [abs] [pdf]
[abstract]
by Tobias Felkl, [and 3 more]Tong Li, Jiajun Liao, and Michael A. Schmidt [hide authors].
The general anomaly-free $U(1)'$ models allow non-universal lepton charges.
We explore the sensitivities of FASER/FASER2, COHERENT and DUNE/T2HK precision
experiments to the new gauge boson $Z'$ and the new CP-even scalar $\phi$. With
non-universal lepton charges, distinctive reaches at FASER/FASER2 emerge in the
regime of low $m_{Z'}$ and small gauge coupling $g_{BL}$ for different $U(1)'$
charge setups. The COHERENT experiment and the future long-baseline experiments
DUNE/T2HK also provide complementary probes to the available parameter space.
For $m_\phi < 2m_{Z'}$, the search for the scalar $\phi$ at FASER/FASER2 is
sensitive to the mixing angle between the scalar singlet and the SM Higgs. In
the case of $m_\phi > 2m_{Z'}$, the kinematically allowed decay $\phi\to Z' Z'$
changes the lifetime and decay rates of the scalar $\phi$. The sensitivity
reach highly depends on the $Z'$ mass and the gauge coupling $g_{BL}$.
- A decoherence explanation of the gallium neutrino anomaly
2306.09422 [abs] [pdf]
[abstract]
by Yasaman Farzan and Thomas Schwetz.
Gallium radioactive source experiments have reported a neutrino-induced event
rate about 20\% lower than expected with a high statistical significance. We
present an explanation of this observation assuming quantum decoherence of the
neutrinos in the gallium detectors at a scale of 2~m. This explanation is
consistent with global data on neutrino oscillations, including solar
neutrinos, if decoherence effects decrease quickly with energy, for instance
with a power law $E_\nu^{-r}$ with $r\simeq 12$. Our proposal does not require
the presence of sterile neutrinos but implies a modification of the standard
quantum mechanical evolution equations for active neutrinos.
- Old Data, New Forensics: The First Second of SN 1987A Neutrino Emission
2306.08024 [abs] [pdf]
[abstract]
by Shirley Weishi Li, [and 3 more]John F. Beacom, Luke F. Roberts, and Francesco Capozzi [hide authors].
The next Milky Way supernova will be an epochal event in multi-messenger
astronomy, critical to tests of supernovae, neutrinos, and new physics.
Realizing this potential depends on having realistic simulations of core
collapse. We investigate the neutrino predictions of nearly all modern models
(1-, 2-, and 3-d) over the first $\simeq$1 s, making the first detailed
comparisons of these models to each other and to the SN 1987A neutrino data.
Even with different methods and inputs, the models generally agree with each
other. However, even considering the low neutrino counts, the models generally
disagree with data. What can cause this? We show that neither neutrino
oscillations nor different progenitor masses appear to be a sufficient
solution. We outline urgently needed work.
- Neutrino oscillation measurements with JUNO in the presence of scalar
NSI
2306.07343 [abs] [pdf]
[abstract]
by Aman Gupta, Debasish Majumdar, and Suprabh Prakash.
Determination of neutrino mass ordering and precision measurement of neutrino
oscillation parameters are the foremost goals of the JUNO experiment. Here, we
explore the capability of JUNO experiment to constrain the scalar non-standard
interactions (sNSI). sNSI appears as a correction to the neutrino mass term in
the Hamiltonian. Our results show that JUNO can put very stringent constraints
on sNSI, particularly for the case of inverted mass ordering. We also check
JUNO's capability to determine mass ordering in the presence of sNSI and
conclude that the possibility to confuse normal (inverted) mass ordering in the
standard scenario (when there is no sNSI) with inverted (normal) ordering in
the presence of sNSI exists only at the $3\sigma$ confidence level and above.
Finally, we also comment on the precision measurements of $\sin^2\theta_{12}$,
$\Delta m^2_{21}$ and $\Delta m^2_{31}$ in the presence of sNSI. We find that
the $1\sigma$-allowed uncertainty in each of these oscillation parameters
depends on the choice of mass ordering, sNSI parameters, and lightest neutrino
mass $\rm m_{lightest}$, wherein a deterioration from a few percent in the case
of standard interactions to $\sim13\%$ in the case of sNSI is possible.
- Beyond Tree Level with Solar Neutrinos: Towards Measuring the Flavor
Composition and CP Violation
2306.03160 [abs] [pdf]
[abstract]
by Vedran Brdar and Xun-Jie Xu.
After being produced as electron neutrinos ($\nu_e$), solar neutrinos
partially change their flavor to $\nu_{\mu}$ and $\nu_{\tau}$ en route to
Earth. Although the flavor ratio of the $\nu_e$ flux to the total flux has been
well measured, the $\nu_{\mu}:\nu_{\tau}$ composition has not yet been
experimentally probed. In this work we show that the $\nu_{\mu}:\nu_{\tau}$
flavor ratio could be measured by utilizing flavor-dependent radiative
corrections in the cross sections for $\nu_{\mu}$ and $\nu_{\tau}$ scattering.
Moreover, since the transition probabilities of $\nu_e$ to $\nu_\mu$ and
$\nu_\tau$ depend on the leptonic CP phase, we also demonstrate that the method
proposed in this work will allow next-generation neutrino experiments to probe
leptonic CP violation through the observation of solar neutrinos.
- CP violation in light neutrino oscillations and heavy neutrino decays: a
general and explicit seesaw-bridged correlation
2306.02362 [abs] [pdf]
[abstract]
by Zhi-zhong Xing.
With the help of a block parametrization of the canonical seesaw flavor
textures in terms of the Euler-like rotation angles and CP-violaing phases, we
derive a general and explicit expression for the Jarlskog invariant of CP
violation in neutrino oscillations and compare it with the CP-violating
asymmetries of heavy Majorana neutrino decays within the minimal seesaw
framework which contains two right-handed neutrino fields. Two simplified
scenarios are discussed to illustrate how direct or indirect the correlation
between these two types of CP violation can be.
- Bounds on lepton non-unitarity and heavy neutrino mixing
2306.01040 [abs] [pdf]
[abstract]
by Mattias Blennow, [and 5 more]Enrique Fernández-Martínez, Josu Hernández-García, Jacobo López-Pavón, Xabier Marcano, and Daniel Naredo-Tuero [hide authors].
We present an updated and improved global fit analysis of current flavor and
electroweak precision observables to derive bounds on unitarity deviations of
the leptonic mixing matrix and on the mixing of heavy neutrinos with the active
flavours. This new analysis is motivated by new and updated experimental
results on key observables such as $V_{ud}$, the invisible decay width of the
$Z$ boson and the $W$ boson mass. It also improves upon previous studies by
considering the full correlations among the different observables and
explicitly calibrating the test statistic, which may present significant
deviations from a $\chi^2$ distribution. The results are provided for three
different Type-I seesaw scenarios: the minimal scenario with only two
additional right-handed neutrinos, the next to minimal one with three extra
neutrinos, and the most general one with an arbitrary number of heavy neutrinos
that we parametrize via a generic deviation from a unitary leptonic mixing
matrix. Additionally, we also analyze the case of generic deviations from
unitarity of the leptonic mixing matrix, not necessarily induced by the
presence of additional neutrinos. This last case relaxes some correlations
among the parameters and is able to provide a better fit to the data.
Nevertheless, inducing only leptonic unitarity deviations avoiding both the
correlations implied by the right-handed neutrino extension as well as more
strongly constrained operators is challenging and would imply significantly
more complex UV completions.
May 2023
- Solar neutrinos with CE$ν$NS and flavor-dependent radiative
corrections
2305.17827 [abs] [pdf]
[abstract]
by Nityasa Mishra and Louis E. Strigari.
We examine solar neutrinos in dark matter detectors including the effects of
flavor-dependent radiative corrections to the CE$\nu$NS cross section. Working
within a full three-flavor framework, and including matter effects within the
Sun and Earth, detectors with thresholds $\lesssim 1$ keV and exposures of
$\sim 100$ ton-year could identify contributions to the cross section beyond
tree level. The differences between the cross sections for the flavors,
combined with the difference in fluxes, would provide a new and unique method
to study the muon and tau components of the solar neutrino flux.
Flavor-dependent corrections induce a small day-night asymmetry of $< |3
\times10^{-4}|$ in the event rate, which if ultimately accessible would provide
a novel probe of flavor oscillations.
- Sun is a cosmic ray TeVatron
2305.17086 [abs] [pdf]
[abstract]
by Prabir Banik, Arunava Bhadra, and Sanjay K. Ghosh.
Very recently, HAWC observatory discovered the high-energy gamma ray emission
from the solar disk during the quiescent stage of the sun, extending the
Fermi-LAT detection of intense, hard emission between 0.1 - 200 GeV to TeV
energies. The flux of these observed gamma-rays is significantly higher than
that theoretically expected from hadronic interactions of galactic cosmic rays
with the solar atmosphere. More importantly, spectral slope of Fermi and HAWC
observed gamma ray energy spectra differ significantly from that of galactic
cosmic rays casting doubt on the prevailing galactic cosmic ray ancestry model
of solar disk gamma rays. In this letter, we argue that the quiet sun can
accelerate cosmic rays to TeV energies with an appropriate flux level in the
solar chromosphere, as the solar chromosphere in its quiet state probably
possesses the required characteristics to accelerate cosmic rays to TeV
energies. Consequently, the mystery of the origin of observed gamma rays from
the solar disc can be resolved consistently through the hadronic interaction of
these cosmic rays with solar matter above the photosphere in a quiet state. The
upcoming IceCube-Gen2 detector should be able to validate the proposed model in
future through observation of TeV muon neutrino flux from the solar disk. The
proposed idea should have major implications on the origin of galactic cosmic
rays.
- Dirac-Majorana neutrino type oscillation induced by a wave dark matter
2305.16900 [abs] [pdf]
[abstract]
by YeolLin ChoeJo, Yechan Kim, and Hye-Sung Lee.
Some properties of a neutrino may differ significantly depending on whether
it is Dirac or Majorana type. The type is determined by the relative size of
Dirac and Majorana masses, which may vary if they arise from an oscillating
scalar dark matter. We show that the change can be significant enough to
convert the neutrino type between Dirac and Majorana periodically while
satisfying constraints on the dark matter. This neutrino type oscillation
predicts periodic modulations in the event rates in various neutrino phenomena
including the neutrinoless double beta decay. As the energy density and, thus,
the oscillation amplitude of the dark matter evolves in the cosmic time scale,
the neutrino masses change accordingly, which provides an interesting link
between the present-time neutrino physics to the early universe cosmology
including the leptogenesis.
- CP and T violation effects in presence of an $\mbox{eV}$ scale sterile
neutrino at long baseline neutrino experiments
2305.16824 [abs] [pdf]
[abstract]
by Sabila Parveen, [and 3 more]Kiran Sharma, Sudhanwa Patra, and Poonam Mehta [hide authors].
An important goal of current and future long baseline neutrino oscillation
experiments pertains to determination of the Dirac-type leptonic $CP$ phase,
$\delta_{13}$. We consider the new physics scenario of an eV scale sterile
neutrino along with three active neutrinos and demonstrate the impact on the
$CP$ and $T$ violation measurements in neutrino oscillations. We address the
question of disentangling the intrinsic effects from extrinsic effects in the
standard three neutrino paradigm as well as the scenario with added light
sterile neutrino. We define a metric to isolate the two kinds of effects and
our approach is general in the sense that it is independent of the choice of
$\delta_{13}$. We study the role of different appearance and disappearance
channels which can contribute to CP and T violation measurements. We perform
the analysis for different long baseline experiments which have different
detection capabilities such as Water Cherenkov (WC) and Liquid Argon Time
Projection Chamber (LArTPC).
- Capability of the proposed long-baseline experiments to probe large
extra dimension
2305.16234 [abs] [pdf]
[abstract]
by Samiran Roy.
Future long-baseline experiments will play an important role in exploring
physics beyond the standard model. One such new physics concept is the large
extra dimension (LED), which provides an elegant solution to the hierarchy
problem. This model also explains the small neutrino mass in a natural way. The
presence of LED modifies the standard neutrino oscillation probabilities.
Hence, the long-baseline experiments are sensitive to the LED parameters. We
explore the potential of the three future long-baseline neutrino experiments,
namely T2HK, ESSnuSB, and DUNE, to probe the LED parameter space. We also
compare the capability of the charged and neutral current measurements at DUNE
to constrain the LED model. We find that T2HK will provide more stringent
bounds on the largest compactification radius ($R_{\rm{ED}}$) compared to the
DUNE and ESSnuSB experiments. At $90\%$ C.L., T2HK can exclude $R_{\rm{ED}}\sim
0.45~(0.425)$ $\mu$m for the normal (inverted) mass hierarchy scenario.
- Probing Non-Standard Neutrino Interactions with Interference: Insights
from Dark Matter and Neutrino Experiments
2305.10836 [abs] [pdf]
[abstract]
by Jong-Chul Park and Gaurav Tomar.
Neutrino-electron scattering experiments play a crucial role in investigating
the non-standard interactions of neutrinos. In certain models, these
interactions can include interference terms that may affect measurements.
Next-generation direct detection experiments, designed primarily for
dark-matter searches, are also getting sensitive to probe the neutrino
properties. We utilise the data from XENONnT, a direct detection experiment,
and Borexino, a low-energy solar neutrino experiment, to investigate the impact
of interference on non-standard interactions. Our study considers models with
an additional $U(1)$, including $U(1)_{B-L}$, $U(1)_{L_e-L_\mu}$, and
$U(1)_{L_e-L_\tau}$, to investigate the impact of interference on non-standard
neutrino interactions. We demonstrate that this interference can lead to a
transition between the considered non-standard interaction models in the energy
range relevant to both the XENONnT and Borexino experiments. This transition
can be used to distinguish among the considered models if any signals are
observed at direct detection or neutrino experiments. Our findings underscore
the importance of accounting for the interference and incorporating both direct
detection and solar neutrino experiments to gain a better understanding of
neutrino interactions and properties.
- Updated T2K measurements of muon neutrino and antineutrino disappearance
using 3.6 $\times$ 10$^{21}$ protons on target
2305.09916 [abs] [pdf]
[abstract]
by M. A. Ramírez, [and 394 more]K. Abe, N. Akhlaq, R. Akutsu, A. Ali, S. Alonso Monsalve, C. Alt, C. Andreopoulos, M. Antonova, S. Aoki, T. Arihara, Y. Asada, Y. Ashida, E. T. Atkin, M. Barbi, G. J. Barker, G. Barr, D. Barrow, M. Batkiewicz-Kwasniak, F. Bench, V. Berardi, L. Berns, S. Bhadra, A. Blanchet, A. Blondel, S. Bolognesi, T. Bonus, S. Bordoni, S. B. Boyd, A. Bravar, C. Bronner, S. Bron, A. Bubak, M. Buizza Avanzini, J. A. Caballero Carretero, N. F. Calabria, S. Cao, D. Carabadjac, A. J. Carter, S. L. Cartwright, M. G. Catanesi, A. Cervera, J. Chakrani, D. Cherdack, P. S. Chong, G. Christodoulou, A. Chvirova, M. Cicerchia, J. Coleman, G. Collazuol, L. Cook, A. Cudd, C. Dalmazzone, T. Daret, Yu. I. Davydov, A. De Roeck, G. De Rosa, T. Dealtry, C. C. Delogu, C. Densham, A. Dergacheva, F. Di Lodovico, S. Dolan, D. Douqa, T. A. Doyle, O. Drapier, J. Dumarchez, P. Dunne, K. Dygnarowicz, A. Eguchi, S. Emery-Schrenk, G. Erofeev, A. Ershova, G. Eurin, D. Fedorova, S. Fedotov, M. Feltre, A. J. Finch, G. A. Fiorentini Aguirre, G. Fiorillo, M. D. Fitton, J. M. Franco Patiño, M. Friend, Y. Fujii, Y. Fukuda, K. Fusshoeller, L. Giannessi, C. Giganti, V. Glagolev, M. Gonin, J. González Rosa, E. A. G. Goodman, A. Gorin, M. Grassi, M. Guigue, D. R. Hadley, J. T. Haigh, P. Hamacher-Baumann, D. A. Harris, M. Hartz, T. Hasegawa, S. Hassani, N. C. Hastings, Y. Hayato, D. Henaff, A. Hiramoto, M. Hogan, J. Holeczek, A. Holin, T. Holvey, N. T. Hong Van, T. Honjo, F. Iacob, A. K. Ichikawa, M. Ikeda, T. Ishida, M. Ishitsuka, H. T. Israel, K. Iwamoto, A. Izmaylov, N. Izumi, M. Jakkapu, B. Jamieson, S. J. Jenkins, C. Jesús-Valls, J. J. Jiang, P. Jonsson, S. Joshi, C. K. Jung, P. B. Jurj, M. Kabirnezhad, A. C. Kaboth, T. Kajita, H. Kakuno, J. Kameda, S. P. Kasetti, Y. Kataoka, Y. Katayama, T. Katori, M. Kawaue, E. Kearns, M. Khabibullin, A. Khotjantsev, T. Kikawa, H. Kikutani, S. King, V. Kiseeva, J. Kisiel, T. Kobata, T. Kobayashi, L. Koch, S. Kodama, A. Konaka, L. L. Kormos, Y. Koshio, A. Kostin, T. Koto, K. Kowalik, Y. Kudenko, Y. Kudo, S. Kuribayashi, R. Kurjata, T. Kutter, M. Kuze, M. La Commara, L. Labarga, K. Lachner, J. Lagoda, S. M. Lakshmi, M. Lamers James, M. Lamoureux, A. Langella, J. -F. Laporte, D. Last, N. Latham, M. Laveder, L. Lavitola, M. Lawe, Y. Lee, C. Lin, S. -K. Lin, R. P. Litchfield, S. L. Liu, W. Li, A. Longhin, K. R. Long, A. Lopez Moreno, L. Ludovici, X. Lu, T. Lux, L. N. Machado, L. Magaletti, K. Mahn, M. Malek, M. Mandal, S. Manly, A. D. Marino, L. Marti-Magro, D. G. R. Martin, M. Martini, J. F. Martin, T. Maruyama, T. Matsubara, V. Matveev, C. Mauger, K. Mavrokoridis, E. Mazzucato, N. McCauley, J. McElwee, K. S. McFarland, C. McGrew, J. McKean, A. Mefodiev, G. D. Megias, P. Mehta, L. Mellet, C. Metelko, M. Mezzetto, E. Miller, A. Minamino, O. Mineev, S. Mine, M. Miura, L. Molina Bueno, S. Moriyama, S. Moriyama, P. Morrison, Th. A. Mueller, D. Munford, L. Munteanu, K. Nagai, Y. Nagai, T. Nakadaira, K. Nakagiri, M. Nakahata, Y. Nakajima, A. Nakamura, H. Nakamura, K. Nakamura, K. D. Nakamura, Y. Nakano, S. Nakayama, T. Nakaya, K. Nakayoshi, C. E. R. Naseby, T. V. Ngoc, V. Q. Nguyen, K. Niewczas, S. Nishimori, Y. Nishimura, K. Nishizaki, T. Nosek, F. Nova, P. Novella, J. C. Nugent, H. M. O'Keeffe, L. O'Sullivan, T. Odagawa, T. Ogawa, R. Okada, K. Okumura, T. Okusawa, N. Ospina, R. A. Owen, Y. Oyama, V. Palladino, V. Paolone, M. Pari, J. Parlone, S. Parsa, J. Pasternak, M. Pavin, D. Payne, G. C. Penn, D. Pershey, L. Pickering, C. Pidcott, G. Pintaudi, C. Pistillo, B. Popov, K. Porwit, M. Posiadala-Zezula, Y. S. Prabhu, F. Pupilli, B. Quilain, T. Radermacher, E. Radicioni, B. Radics, P. N. Ratoff, M. Reh, C. Riccio, E. Rondio, S. Roth, A. Rubbia, A. C. Ruggeri, C. A. Ruggles, A. Rychter, K. Sakashita, F. Sánchez, G. Santucci, C. M. Schloesser, K. Scholberg, M. Scott, Y. Seiya, T. Sekiguchi, H. Sekiya, D. Sgalaberna, A. Shaikhiev, F. Shaker, M. Shiozawa, W. Shorrock, A. Shvartsman, N. Skrobova, K. Skwarczynski, D. Smyczek, M. Smy, J. T. Sobczyk, H. Sobel, F. J. P. Soler, Y. Sonoda, A. J. Speers, R. Spina, I. A. Suslov, S. Suvorov, A. Suzuki, S. Y. Suzuki, Y. Suzuki, A. A. Sztuc, M. Tada, S. Tairafune, S. Takayasu, A. Takeda, Y. Takeuchi, K. Takifuji, H. K. Tanaka, Y. Tanihara, M. Tani, A. Teklu, V. V. Tereshchenko, N. Teshima, N. Thamm, L. F. Thompson, W. Toki, C. Touramanis, T. Towstego, K. M. Tsui, T. Tsukamoto, M. Tzanov, Y. Uchida, M. Vagins, D. Vargas, G. Vasseur, C. Vilela, E. Villa, W. G. S. Vinning, U. Virginet, T. Vladisavljevic, T. Wachala, J. G. Walsh, Y. Wang, L. Wan, D. Wark, M. O. Wascko, A. Weber, R. Wendell, M. J. Wilking, C. Wilkinson, J. R. Wilson, K. Wood, C. Wret, J. Xia, Y. -h. Xu, K. Yamamoto, T. Yamamoto, C. Yanagisawa, G. Yang, T. Yano, K. Yasutome, N. Yershov, U. Yevarouskaya, M. Yokoyama, Y. Yoshimoto, N. Yoshimura, M. Yu, R. Zaki, A. Zalewska, J. Zalipska, K. Zaremba, G. Zarnecki, X. Zhao, T. Zhu, M. Ziembicki, E. D. Zimmerman, M. Zito, and S. Zsoldos [hide authors].
Muon neutrino and antineutrino disappearance probabilities are identical in
the standard three-flavor neutrino oscillation framework, but CPT violation and
non-standard interactions can violate this symmetry. In this work we report the
measurements of $\sin^{2} \theta_{23}$ and $\Delta m_{32}^2$ independently for
neutrinos and antineutrinos. The aforementioned symmetry violation would
manifest as an inconsistency in the neutrino and antineutrino oscillation
parameters. The analysis discussed here uses a total of 1.97$\times$10$^{21}$
and 1.63$\times$10$^{21}$ protons on target taken with a neutrino and
antineutrino beam respectively, and benefits from improved flux and
cross-section models, new near detector samples and more than double the data
reducing the overall uncertainty of the result. No significant deviation is
observed, consistent with the standard neutrino oscillation picture.
- Exploring Models with Modular Symmetry in Neutrino Oscillation
Experiments
2305.08576 [abs] [pdf]
[abstract]
by Priya Mishra, [and 4 more]Mitesh Kumar Behera, Papia Panda, Monojit Ghosh, and Rukmani Mohanta [hide authors].
Our study aims to investigate the viability of neutrino mass models that
arise from discrete non-Abelian modular symmetry groups, i.e., $\Gamma_N$ with
($N=1,2,3,\dots$) in the future neutrino experiments T2HK, DUNE, and JUNO.
Modular symmetry reduces the usage of flavon fields compared to the
conventional discrete flavor symmetry models. Theories based on modular
symmetries predict the values of leptonic mixing parameters, and therefore,
these models can be tested in future neutrino experiments. In this study, we
consider three models based on the $A_4$ modular symmetry, i.e., Model-A, B,
and C such a way that they predict different values of the oscillation
parameters but still allowed with respect to the current data. In the future,
it is expected that T2HK, DUNE, and JUNO will measure the neutrino oscillation
parameters very precisely, and therefore, some of these models can be excluded
in the future by these experiments. We have estimated the prediction of these
models numerically and then used them as input to scrutinize these models in
the neutrino experiments. Assuming the future best-fit values of $\theta_{23}$
and $\delta_{\rm CP}$ remain the same as the current one, our results show that
at $5 \sigma$ C.L, Model-A can be excluded by T2HK whereas Model-B can be
excluded by both T2HK and DUNE. Model-C cannot be excluded by T2HK and DUNE at
$5 \sigma$ C.L. Further; our results show that JUNO alone can exclude Model-B
at an extremely high confidence level if the future best-fit of $\theta_{12}$
remains at the current-one. We have also identified the region in the
$\theta_{23}$ - $\delta_{\rm CP}$ parameter space, for which Model-A cannot be
separated from Model-B in T2HK and DUNE.
- Exploring Ultralight Scalar Assistance in Sterile Neutrino Dark Matter:
Cold Spectrum and Unusual X/Gamma-ray Signatures
2305.08095 [abs] [pdf]
[abstract]
by Yuxuan He, [and 3 more]Jia Liu, Xiaolin Ma, and Xiao-Ping Wang [hide authors].
We present a scalar-driven sterile neutrino production model where the
interaction with the ultralight scalar field modifies the oscillation
production of sterile neutrinos in the early universe. The model effectively
suppresses the production of sterile neutrinos at low temperatures due to the
heavy scalar mass, resulting in a colder matter power spectrum that avoids
constraints from small-scale structure observations. In this model, the
dominant dark matter relic is from sterile neutrinos, with only a small
fraction originating from the ultralight scalar. Furthermore, the model
predicts a detectable X/Gamma-ray flux proportional to the cubic density of
local sterile neutrinos for a light scalar mass due to the light scalar
coupling tosterile neutrinos. This distinguishes our model from normal decaying
dark matter, which has a linear dependence on the density. In addition, the
model predicts a potential low-energy monochromatic neutrino signal that can be
detectable by future neutrino telescopes.
- Global constraints on non-standard neutrino interactions with quarks and
electrons
2305.07698 [abs] [pdf]
[abstract]
by Pilar Coloma, [and 4 more]M. C. Gonzalez-Garcia, Michele Maltoni, João Paulo Pinheiro, and Salvador Urrea [hide authors].
We derive new constraints on effective four-fermion neutrino non-standard
interactions with both quarks and electrons. This is done through the global
analysis of neutrino oscillation data and measurements of coherent elastic
neutrino-nucleus scattering (CEvNS) obtained with different nuclei. In doing
so, we include not only the effects of new physics on neutrino propagation but
also on the detection cross section in neutrino experiments which are sensitive
to the new physics. We consider both vector and axial-vector neutral-current
neutrino interactions and, for each case, we include simultaneously all allowed
effective operators in flavour space. To this end, we use the most general
parametrization for their Wilson coefficients under the assumption that their
neutrino flavour structure is independent of the charged fermion participating
in the interaction. The status of the LMA-D solution is assessed for the first
time in the case of new interactions taking place simultaneously with up
quarks, down quarks, and electrons. One of the main results of our work are the
presently allowed regions for the effective combinations of non-standard
neutrino couplings, relevant for long-baseline and atmospheric neutrino
oscillation experiments.
- Identifying Extended PeVatron Sources via Neutrino Shower Detection
2305.07043 [abs] [pdf]
[abstract]
by Takahiro Sudoh and John F. Beacom.
Identifying the Milky Way's very high energy hadronic cosmic-ray accelerators
-- the PeVatrons -- is a critical problem. While gamma-ray observations reveal
promising candidate sources, neutrino detection is needed for certainty, and
this has not yet been successful. Why not? There are several possibilities, as
we delineated in a recent paper [T. Sudoh and J. F. Beacom, Phys. Rev. D 107,
043002 (2023)]. Here we further explore the possibility that the challenges
arise because PeVatrons have a large angular extent, either due to cosmic-ray
propagation effects or due to clusters of sources. We show that while extended
neutrino sources could be missed in the commonly used muon-track channel, they
could be discovered in the all-flavor shower channel, which has a lower
atmospheric-neutrino background flux per solid angle. Intrinsically, showers
are quite directional and would appear so in water-based detectors like the
future KM3NeT, even though they are presently badly smeared by light scattering
in ice-based detectors like IceCube. Our results motivate new shower-based
searches as part of the comprehensive approach to identifying the Milky Way's
hadronic PeVatrons.
- Probing the Local Dark Matter Halo with Neutrino Oscillations
2305.06441 [abs] [pdf]
[abstract]
by Tony Gherghetta and Andrey Shkerin.
Dark matter particles can form halos gravitationally bound to massive
astrophysical objects. The Earth could have such a halo where depending on the
particle mass, the halo either extends beyond the surface or is confined to the
Earth's interior. We consider the possibility that if dark matter particles are
coupled to neutrinos, then neutrino oscillations can be used to probe the
Earth's dark matter halo. In particular, atmospheric neutrinos traversing the
Earth can be sensitive to a small size, interior halo, inaccessible by other
means. Depending on the halo mass and neutrino energy, constraints on the dark
matter-neutrino couplings are obtained from the halo corrections to the
neutrino oscillations.
- Neutrino CPT violation in the solar sector
2305.06384 [abs] [pdf]
[abstract]
by Gabriela Barenboim, [and 3 more]Pablo Martínez-Miravé, Christoph A. Ternes, and Mariam Tórtola [hide authors].
In this paper we place new bounds on CPT violation in the solar neutrino
sector analyzing the results from solar experiments and KamLAND. We also
discuss the sensitivity of the next-generation experiments DUNE and
Hyper-Kamiokande, which will provide accurate measurements of the solar
neutrino oscillation parameters. The joint analysis of both experiments will
further improve the precision due to cancellations in the systematic
uncertainties regarding the solar neutrino flux. In combination with the
next-generation reactor experiment JUNO, the bound on CPT violation in the
solar sector could be improved by one order of magnitude in comparison with
current constraints. The distinguishability among CPT-violating neutrino
oscillations and neutrino non-standard interactions in the solar sector is also
addressed.
- Flavor-dependent long-range neutrino interactions in DUNE & T2HK: alone
they constrain, together they discover
2305.05184 [abs] [pdf]
[abstract]
by Masoom Singh, Mauricio Bustamante, and Sanjib Kumar Agarwalla.
Discovering new neutrino interactions would represent evidence of physics
beyond the Standard Model. We focus on new flavor-dependent long-range neutrino
interactions mediated by ultra-light mediators, with masses below $10^{-10}$
eV, introduced by new lepton-number gauge symmetries $L_e-L_\mu$, $L_e-L_\tau$,
and $L_\mu-L_\tau$. Because the interaction range is ultra-long, nearby and
distant matter - primarily electrons and neutrons - in the Earth, Moon, Sun,
Milky Way, and the local Universe, may source a large matter potential that
modifies neutrino oscillation probabilities. The upcoming Deep Underground
Neutrino Experiment (DUNE) and the Tokai-to-Hyper-Kamiokande (T2HK)
long-baseline neutrino experiments will provide an opportunity to search for
these interactions, thanks to their high event rates and well-characterized
neutrino beams. We forecast their probing power. Our results reveal novel
perspectives. Alone, DUNE and T2HK may strongly constrain long-range
interactions, setting new limits on their coupling strength for mediators
lighter than $10^{-18}$ eV. However, if the new interactions are subdominant,
then both DUNE and T2HK, together, will be needed to discover them, since their
combination lifts parameter degeneracies that weaken their individual
sensitivity. DUNE and T2HK, especially when combined, provide a valuable
opportunity to explore physics beyond the Standard Model.
- Constraints on dark matter-neutrino scattering from the Milky-Way
satellites and subhalo modeling for dark acoustic oscillations
2305.01913 [abs] [pdf]
[abstract]
by Kensuke Akita and Shin'ichiro Ando.
The elastic scattering between dark matter (DM) and radiation can potentially
explain small-scale observations that the cold dark matter faces as a
challenge, as damping density fluctuations via dark acoustic oscillations in
the early universe erases small-scale structure. We study a semi-analytical
subhalo model for interacting dark matter with radiation, based on the extended
Press-Schechter formalism and subhalos' tidal evolution prescription. We also
test the elastic scattering between DM and neutrinos using observations of
Milky-Way satellites from the Dark Energy Survey and PanSTARRS1. We
conservatively impose strong constraints on the DM-neutrino scattering cross
section of $\sigma_{{\rm DM}\text{-}\nu,n}\propto E_\nu^n$ $(n=0,2,4)$ at
$95\%$ confidence level (CL), $\sigma_{{\rm DM}\text{-}\nu,0}< 10^{-32}\ {\rm
cm^2}\ (m_{\rm DM}/{\rm GeV})$, $\sigma_{{\rm DM}\text{-}\nu,2}< 10^{-43}\ {\rm
cm^2}\ (m_{\rm DM}/{\rm GeV})(E_\nu/E_{\nu}^0)^2$ and $\sigma_{{\rm
DM}\text{-}\nu,4}< 10^{-54}\ {\rm cm^2}\ (m_{\rm DM}/{\rm
GeV})(E_\nu/E_{\nu}^0)^4$, where $E_\nu^0$ is the average momentum of relic
cosmic neutrinos today, $E_\nu^0 \simeq 3.15 T_\nu^0 \simeq 6.1\ {\rm K}$. By
imposing a satellite forming condition, we obtain the strongest upper bounds on
the DM-neutrino cross section at $95\%$ CL, $\sigma_{{\rm DM}\text{-}\nu,0}<
4\times 10^{-34}\ {\rm cm^2}\ (m_{\rm DM}/{\rm GeV})$, $\sigma_{{\rm
DM}\text{-}\nu,2}< 10^{-46}\ {\rm cm^2}\ (m_{\rm DM}/{\rm
GeV})(E_\nu/E_{\nu}^0)^2$ and $\sigma_{{\rm DM}\text{-}\nu,4}< 7\times
10^{-59}\ {\rm cm^2}\ (m_{\rm DM}/{\rm GeV})(E_\nu/E_{\nu}^0)^4$.
- Precision CMB constraints on eV-scale bosons coupled to neutrinos
2305.01692 [abs] [pdf]
[abstract]
by Stefan Sandner, Miguel Escudero, and Samuel J. Witte.
The cosmic microwave background (CMB) has proven to be an invaluable tool for
studying the properties and interactions of neutrinos, providing insight not
only into the sum of neutrino masses but also the free streaming nature of
neutrinos prior to recombination. The CMB is a particularly powerful probe of
new eV-scale bosons interacting with neutrinos, as these particles can
thermalize with neutrinos via the inverse decay process, $\nu\bar{\nu}
\rightarrow X$, and suppress neutrino free streaming near recombination -- even
for couplings as small as $\lambda_\nu \sim \mathcal{O}(10^{-13})$. Here, we
revisit CMB constraints on such bosons, improving upon a number of
approximations previously adopted in the literature and generalizing the
constraints to a broader class of models. This includes scenarios in which the
boson is either spin-$0$ or spin-$1$, the number of interacting neutrinos is
either $N_{\rm int} = 1,2 $ or $3$, and the case in which a primordial
abundance of the species is present. We apply these bounds to well-motivated
models, such as the singlet majoron model or a light $U(1)_{L_\mu-L_\tau}$
gauge boson, and find that they represent the leading constraints for masses
$m_X\sim 1\, {\rm eV}$. Finally, we revisit the extent to which neutrino-philic
bosons can ameliorate the Hubble tension, and find that recent improvements in
the understanding of how such bosons damp neutrino free streaming reduces the
previously found success of this proposal.
- Extended Analysis of Neutrino-Dark Matter Interactions with Small-Scale
CMB Experiments
2305.01383 [abs] [pdf]
[abstract]
by Philippe Brax, [and 4 more]Carsten van de Bruck, Eleonora Di Valentino, William Giarè, and Sebastian Trojanowski [hide authors].
We explore an extension of the standard $\Lambda$CDM model by including an
interaction between neutrinos and dark matter, and making use of the ground
based telescope data of the Cosmic Microwave Background (CMB) from the Atacama
Cosmology Telescope (ACT). An indication for a non-zero coupling between dark
matter and neutrinos (both assuming a temperature independent and $T^2$
dependent cross-section) is obtained at the 1$\sigma$ level coming from the ACT
CMB data alone and when combined with the Planck CMB and Baryon Acoustic
Oscillations (BAO) measurements. This result is confirmed by both fixing the
effective number of relativistic degrees of freedom in the early Universe to
the Standard Model value of $N_{\rm eff}=3.044$, and allowing $N_{\rm eff}$ to
be a free cosmological parameter. Furthermore, when performing a Bayesian model
comparison, the interacting $\nu$DM (+$N_{\rm eff}$) scenario is mostly
preferred over a baseline $\Lambda$CDM (+$N_{\rm eff}$) cosmology. The
preferred value is then used as a benchmark and the potential implications of
dark matter's interaction with a sterile neutrino are discussed.
April 2023
- Measurement of Atmospheric Neutrino Mixing with Improved IceCube
DeepCore Calibration and Data Processing
2304.12236 [abs] [pdf]
[abstract]
by IceCube Collaboration, [and 407 more]R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, V. Basu, R. Bay, J. J. Beatty, K. -H. Becker, J. Becker Tjus, J. Beise, C. Bellenghi, C. Benning, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, G. Binder, E. Blaufuss, S. Blot, F. Bontempo, J. Y. Book, C. Boscolo Meneguolo, S. Böser, O. Botner, J. Böttcher, E. Bourbeau, J. Braun, B. Brinson, J. Brostean-Kaiser, R. T. Burley, R. S. Busse, D. Butterfield, M. A. Campana, K. Carloni, E. G. Carnie-Bronca, S. Chattopadhyay, N. Chau, C. Chen, Z. Chen, D. Chirkin, S. Choi, B. A. Clark, L. Classen, A. Coleman, G. H. Collin, A. Connolly, J. M. Conrad, P. Coppin, P. Correa, S. Countryman, D. F. Cowen, P. Dave, C. De Clercq, J. J. DeLaunay, D. Delgado, H. Dembinski, S. Deng, K. Deoskar, A. Desai, P. Desiati, K. D. de Vries, G. de Wasseige, T. DeYoung, A. Diaz, J. C. Díaz-Vélez, M. Dittmer, A. Domi, H. Dujmovic, M. A. DuVernois, T. Ehrhardt, P. Eller, S. El Mentawi, R. Engel, H. Erpenbeck, J. Evans, P. A. Evenson, K. L. Fan, K. Fang, K. Farrag, A. R. Fazely, A. Fedynitch, N. Feigl, S. Fiedlschuster, C. Finley, L. Fischer, D. Fox, A. Franckowiak, E. Friedman, A. Fritz, P. Fürst, T. K. Gaisser, J. Gallagher, E. Ganster, A. Garcia, L. Gerhardt, A. Ghadimi, C. Glaser, T. Glauch, T. Glüsenkamp, N. Goehlke, J. G. Gonzalez, S. Goswami, D. Grant, S. J. Gray, O. Gries, S. Griffin, S. Griswold, C. Günther, P. Gutjahr, C. Haack, A. Hallgren, R. Halliday, L. Halve, F. Halzen, H. Hamdaoui, M. Ha Minh, K. Hanson, J. Hardin, A. A. Harnisch, P. Hatch, A. Haungs, K. Helbing, J. Hellrung, F. Henningsen, L. Heuermann, N. Heyer, S. Hickford, A. Hidvegi, J. Hignight, C. Hill, G. C. Hill, K. D. Hoffman, S. Hori, K. Hoshina, W. Hou, T. Huber, K. Hultqvist, M. Hünnefeld, R. Hussain, K. Hymon, S. In, A. Ishihara, M. Jacquart, O. Janik, M. Jansson, G. S. Japaridze, M. Jeong, M. Jin, B. J. P. Jones, D. Kang, W. Kang, X. Kang, A. Kappes, D. Kappesser, L. Kardum, T. Karg, M. Karl, A. Karle, U. Katz, M. Kauer, J. L. Kelley, A. Khatee Zathul, A. Kheirandish, J. Kiryluk, S. R. Klein, A. Kochocki, R. Koirala, H. Kolanoski, T. Kontrimas, L. Köpke, C. Kopper, D. J. Koskinen, P. Koundal, M. Kovacevich, M. Kowalski, T. Kozynets, J. Krishnamoorthi, K. Kruiswijk, E. Krupczak, A. Kumar, E. Kun, N. Kurahashi, N. Lad, C. Lagunas Gualda, M. Lamoureux, M. J. Larson, S. Latseva, F. Lauber, J. P. Lazar, J. W. Lee, K. Leonard DeHolton, A. Leszczyńska, M. Lincetto, Q. R. Liu, M. Liubarska, E. Lohfink, C. Love, C. J. Lozano Mariscal, L. Lu, F. Lucarelli, A. Ludwig, W. Luszczak, Y. Lyu, W. Y. Ma, J. Madsen, K. B. M. Mahn, Y. Makino, E. Manao, S. Mancina, W. Marie Sainte, I. C. Mariş, S. Marka, Z. Marka, M. Marsee, I. Martinez-Soler, R. Maruyama, F. Mayhew, T. McElroy, F. McNally, J. V. Mead, K. Meagher, S. Mechbal, A. Medina, M. Meier, Y. Merckx, L. Merten, J. Micallef, T. Montaruli, R. W. Moore, Y. Morii, R. Morse, M. Moulai, T. Mukherjee, R. Naab, R. Nagai, M. Nakos, U. Naumann, J. Necker, M. Neumann, H. Niederhausen, M. U. Nisa, A. Noell, S. C. Nowicki, A. Obertacke Pollmann, V. O'Dell, M. Oehler, B. Oeyen, A. Olivas, R. Orsoe, J. Osborn, E. O'Sullivan, H. Pandya, N. Park, G. K. Parker, E. N. Paudel, L. Paul, C. Pérez de los Heros, J. Peterson, S. Philippen, S. Pieper, A. Pizzuto, M. Plum, A. Pontén, Y. Popovych, M. Prado Rodriguez, B. Pries, R. Procter-Murphy, G. T. Przybylski, J. Rack-Helleis, K. Rawlins, Z. Rechav, A. Rehman, P. Reichherzer, G. Renzi, E. Resconi, S. Reusch, W. Rhode, M. Richman, B. Riedel, A. Rifaie, E. J. Roberts, S. Robertson, S. Rodan, G. Roellinghoff, M. Rongen, C. Rott, T. Ruhe, L. Ruohan, D. Ryckbosch, I. Safa, J. Saffer, D. Salazar-Gallegos, P. Sampathkumar, S. E. Sanchez Herrera, A. Sandrock, M. Santander, S. Sarkar, S. Sarkar, J. Savelberg, P. Savina, M. Schaufel, H. Schieler, S. Schindler, L. Schlickmann, B. Schlüter, F. Schlüter, T. Schmidt, J. Schneider, F. G. Schröder, L. Schumacher, G. Schwefer, S. Sclafani, D. Seckel, M. Seikh, S. Seunarine, R. Shah, A. Sharma, S. Shefali, N. Shimizu, M. Silva, B. Skrzypek, B. Smithers, R. Snihur, J. Soedingrekso, A. Søgaard, D. Soldin, P. Soldin, G. Sommani, C. Spannfellner, G. M. Spiczak, C. Spiering, M. Stamatikos, T. Stanev, T. Stezelberger, T. Stürwald, T. Stuttard, G. W. Sullivan, I. Taboada, S. Ter-Antonyan, A. Terliuk, M. Thiesmeyer, W. G. Thompson, J. Thwaites, S. Tilav, K. Tollefson, C. Tönnis, S. Toscano, D. Tosi, A. Trettin, C. F. Tung, R. Turcotte, J. P. Twagirayezu, B. Ty, M. A. Unland Elorrieta, A. K. Upadhyay, K. Upshaw, N. Valtonen-Mattila, J. Vandenbroucke, N. van Eijndhoven, D. Vannerom, J. van Santen, J. Vara, J. Veitch-Michaelis, M. Venugopal, M. Vereecken, S. Verpoest, D. Veske, C. Walck, T. B. Watson, C. Weaver, P. Weigel, A. Weindl, J. Weldert, C. Wendt, J. Werthebach, M. Weyrauch, N. Whitehorn, C. H. Wiebusch, N. Willey, D. R. Williams, A. Wolf, M. Wolf, G. Wrede, X. W. Xu, J. P. Yanez, E. Yildizci, S. Yoshida, R. Young, F. Yu, S. Yu, T. Yuan, Z. Zhang, and P. Zhelnin [hide authors].
We describe a new data sample of IceCube DeepCore and report on the latest
measurement of atmospheric neutrino oscillations obtained with data recorded
between 2011-2019. The sample includes significant improvements in data
calibration, detector simulation, and data processing, and the analysis
benefits from a detailed treatment of systematic uncertainties, with
significantly higher level of detail since our last study. By measuring the
relative fluxes of neutrino flavors as a function of their reconstructed
energies and arrival directions we constrain the atmospheric neutrino mixing
parameters to be $\sin^2\theta_{23} = 0.51\pm 0.05$ and $\Delta m^2_{32} =
2.41\pm0.07\times 10^{-3}\mathrm{eV}^2$, assuming a normal mass ordering. The
resulting 40\% reduction in the error of both parameters with respect to our
previous result makes this the most precise measurement of oscillation
parameters using atmospheric neutrinos. Our results are also compatible and
complementary to those obtained using neutrino beams from accelerators, which
are obtained at lower neutrino energies and are subject to different sources of
uncertainties.
- Neutrino Constraints and the ATOMKI X17 Anomaly
2304.09877 [abs] [pdf]
[abstract]
by Peter B. Denton and Julia Gehrlein.
Recent data from the ATOMKI group continues to confirm their claim of the
existence of a new $\sim17$ MeV particle. We review and numerically analyze the
data and then put into context constraints from other experiments, notably
neutrino scattering experiments such as the latest reactor anti-neutrino
coherent elastic neutrino nucleus scattering data and unitarity constraints
from solar neutrino observations. We show that minimal scenarios are disfavored
and discuss the model requirements to evade these constraints.
- Astrophysical neutrino point sources as a probe of new physics
2304.08533 [abs] [pdf]
[abstract]
by C. Döring and S. Vogl.
Recently, the IceCube collaboration observed a neutrino excess in the
direction of NGC 1068 with high statistical significance. This constitutes the
second detection of an astrophysical neutrino point source after the discovery
of a variable emission originating from the blazar TXS~0506+056. Neutrinos
emitted by these sources traverse huge, well-determined distances on their way
to Earth. This makes them a promising tool to test new physics in the neutrino
sector. We consider secret interactions with the cosmic neutrino background and
discuss their impact on the flux of neutrino point sources. The observation of
emission from NGC 1068 and TXS 0506+056 can then be used to put limits on the
strength of the interaction. We find that our ignorance of the absolute
neutrino masses has a strong impact and, therefore, we present limits in two
benchmark scenarios with the sum of the neutrino masses around their lower and
upper limits.
- Future leptonic CP phase determination in the presence of NSI
2304.05545 [abs] [pdf]
[abstract]
by Luis A. Delgadillo and O. G. Miranda.
The precise determination of the leptonic CP phase is one of the major goals
for future generation Long Baseline experiments. On the other hand, if new
physics beyond the Standard Model exists, a robust determination of such a CP
phase may be a challenge. Moreover, it has been pointed out that, in this
scenario, an apparent discrepancy in the CP phase measurement at different
experiments may arise. In this work, we investigate the robustness of the
determination of the Dirac CP-phase at several long-baseline configurations:
ESSnuSB, T2HKK, and a DUNE-like experiment. We use the non-standard neutrino
interactions (NSI) formalism as a framework. We found that complementary
between ESSnuSB and a DUNE-like experiment enhances the robustness in the
determination of the CP-phase, even in the presence of matter NSI. Moreover,
the T2HKK proposal can help to constrain the matter NSI parameters.
- JUNO as a Probe of the Pseudo-Dirac Nature using Solar Neutrinos
2304.05418 [abs] [pdf]
[abstract]
by Jack Franklin, Yuber F. Perez-Gonzalez, and Jessica Turner.
It remains a possibility that neutrinos are pseudo-Dirac states, such that a
generation is composed of two maximally mixed Majorana neutrinos separated by a
very small mass difference. We explore the physics potential of the JUNO
experiment in constraining this possibility using the measurement of solar
neutrinos. In particular, we investigate cases where one or three sterile
states are present in addition to the active states. We consider two scenarios:
one where JUNO's energy threshold allows for the measurement of $pp$ solar
neutrinos, and the case where JUNO can only measure $^7$Be neutrinos and above.
We find that JUNO will be able to constrain pseudo-Dirac mass splittings of
$\delta m^2 \gtrsim 2.9\times 10^{-13}~{\rm eV^2}$ for the scenario including
$pp$ solar neutrinos, and $\delta m^2 \gtrsim 1.9\times 10^{-12}~{\rm eV^2}$
when the measurement only considers $^7$Be monochromatic neutrinos, at the
$3\sigma$ C.L. Thus, including $pp$ neutrinos will be crucial for JUNO to
improve current constraints on the pseudo-Dirac scenario from solar neutrinos.
- Right-Handed Neutrino Dark Matter with Forbidden Annihilation
2304.02997 [abs] [pdf]
[abstract]
by Yu Cheng, [and 3 more]Shao-Feng Ge, Jie Sheng, and Tsutomu T. Yanagida [hide authors].
The seesaw mechanism with three right-handed neutrinos has one as a
well-motivated dark matter candidate if stable and the other two can explain
baryon asymmetry via the thermal leptogenesis scenario. We explore the
possibility of introducing additional particles to make the right-handed
neutrino dark matter in thermal equilibrium and freeze out through a forbidden
annihilation channel. Nowadays in the Universe, this forbidden channel can be
reactivated by a strong gravitational potential such as the supermassive black
hole in our galaxy center. The Fermi-LAT gamma ray data and dark matter relic
density require this right-handed neutrino dark matter to have mass below
$100\,$GeV and the existence of an additional boson $\phi$ that can be tested
at future lepton colliders.
- Testing generalized neutrino interactions with PTOLEMY
2304.02505 [abs] [pdf]
[abstract]
by Indra Kumar Banerjee, [and 3 more]Ujjal Kumar Dey, Newton Nath, and Saadat Salman Shariff [hide authors].
There are several unanswered questions regarding neutrinos which pave the way
for physics beyond the standard model (SM) of particle physics. Generalized
interactions of neutrinos provide a way to characterize these effects in a
manner which is even more general than the oft-studied non-standard neutrino
interactions. These interactions are described by higher dimensional operators
maintaining the SM gauge symmetries. On the other hand cosmic neutrino
background, although yet to be detected directly, is a robust prediction of the
SM and the standard cosmology. We perform a global analysis of the relevant
generalized neutrino interactions which are expressly relevant for the proposed
cosmic neutrino detector PTOLEMY. The electron spectrum due to the capture of
cosmic neutrinos on radioactive tritium gets modified due to the presence of
these generalized interactions. We also show how the differential electron
spectrum is sensitive to the finite experimental resolution, mass of the
lightest neutrino eigenstate, the strength of these interactions and the
ordering of neutrino mass.
- Anomalous Tau Neutrino Appearance from Light Mediators in Short-Baseline
Neutrino Experiments
2304.02031 [abs] [pdf]
[abstract]
by P. S. Bhupal Dev, [and 3 more]Bhaskar Dutta, Tao Han, and Doojin Kim [hide authors].
We point out a new mechanism giving rise to anomalous tau neutrino appearance
at the near detectors of beam-focused neutrino experiments, without extending
the neutrino sector. The charged mesons ($\pi^\pm, K^\pm$) produced and focused
in the target-horn system can decay to a (neutrino-philic) light mediator via
the helicity-unsuppressed three-body decays. If such a mediator carries
non-vanishing hadronic couplings, it can also be produced via the
bremsstrahlung of the incident proton beam. The subsequent decay of the
mediator to a tau neutrino pair results in tau neutrino detection at the near
detectors, which is unexpected under the standard three-flavor neutrino
oscillation paradigm. We argue that the signal flux from the charged meson
decays can be significant enough to discover the light mediator signal at the
on-axis liquid-argon near detector of the DUNE experiment, due to the focusing
of charged mesons. In addition, we show that ICARUS-NuMI, an off-axis near
detector of the NuMI beam, as well as DUNE, can observe a handful of tau
neutrino events induced by beam-proton bremsstrahlung.
- Implications of NSI constraints from ANTARES and IceCube on a simplified
$Z^\prime$ model
2304.01388 [abs] [pdf]
[abstract]
by J. M. Cabarcas, A. Parada, and Nestor Quintero.
Recently the neutrino experiments ANTARES and IceCube have released new
constraints to the non-standard neutrino interaction (NSI) parameter
$\epsilon^d_{\mu\tau}$ (flavor off-diagonal). These new constraints are
stronger than those obtained from a combination of COHERENT and neutrino
oscillation data. In the light of the recent constraints from ANTARES and
IceCube data on the NSI parameter $\epsilon^d_{\mu\tau}$, in this work, we
study the new physics implications on the parameter space of a simplified
$Z^\prime$ model with lepton flavor violating ($\mu\tau$) couplings. For a
$Z^\prime$ boson with a mass heavier than the $\tau$ lepton, our results show
that ANTARES and IceCube put strong constraints to such a new physics scenario
with $\mu\tau$ couplings. In addition, these neutrino experiments can exclude a
similar region than ATLAS experiment, showing the potential to provide
complementary information to the one obtained from direct searches at the Large
Hadron Collider. The impact of the expected sensitivity reach on
$\epsilon^d_{\mu\tau}$ at DUNE experiment is also studied.
- IceCat-1: the IceCube Event Catalog of Alert Tracks
2304.01174 [abs] [pdf]
[abstract]
by R. Abbasi, [and 393 more]M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, V. Basu, R. Bay, J. J. Beatty, K. -H. Becker, J. Becker Tjus, J. Beise, C. Bellenghi, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, G. Binder, D. Bindig, E. Blaufuss, S. Blot, F. Bontempo, J. Y. Book, C. Boscolo Meneguolo, S. Böser, O. Botner, J. Böttcher, E. Bourbeau, J. Braun, B. Brinson, J. Brostean-Kaiser, R. T. Burley, R. S. Busse, D. Butterfield, M. A. Campana, K. Carloni, E. G. Carnie-Bronca, S. Chattopadhyay, N. Chau, C. Chen, Z. Chen, D. Chirkin, S. Choi, B. A. Clark, L. Classen, A. Coleman, G. H. Collin, A. Connolly, J. M. Conrad, P. Coppin, P. Correa, S. Countryman, D. F. Cowen, P. Dave, C. De Clercq, J. J. DeLaunay, D. Delgado, H. Dembinski, S. Deng, K. Deoskar, A. Desai, P. Desiati, K. D. de Vries, G. de Wasseige, T. DeYoung, A. Diaz, J. C. Díaz-Vélez, M. Dittmer, A. Domi, H. Dujmovic, M. A. DuVernois, T. Ehrhardt, P. Eller, R. Engel, H. Erpenbeck, J. Evans, P. A. Evenson, K. L. Fan, K. Fang, K. Farrag, A. R. Fazely, A. Fedynitch, N. Feigl, S. Fiedlschuster, C. Finley, L. Fischer, D. Fox, A. Franckowiak, E. Friedman, A. Fritz, P. Fürst, T. K. Gaisser, J. Gallagher, E. Ganster, A. Garcia, L. Gerhardt, A. Ghadimi, C. Glaser, T. Glauch, T. Glüsenkamp, N. Goehlke, J. G. Gonzalez, S. Goswami, D. Grant, S. J. Gray, S. Griffin, S. Griswold, C. Günther, P. Gutjahr, C. Haack, A. Hallgren, R. Halliday, L. Halve, F. Halzen, H. Hamdaoui, M. Ha Minh, K. Hanson, J. Hardin, A. A. Harnisch, P. Hatch, A. Haungs, K. Helbing, J. Hellrung, F. Henningsen, L. Heuermann, N. Heyer, S. Hickford, A. Hidvegi, C. Hill, G. C. Hill, K. D. Hoffman, K. Hoshina, W. Hou, T. Huber, K. Hultqvist, M. Hünnefeld, R. Hussain, K. Hymon, S. In, A. Ishihara, M. Jacquart, O. Janik, M. Jansson, G. S. Japaridze, K. Jayakumar, M. Jeong, M. Jin, B. J. P. Jones, D. Kang, W. Kang, X. Kang, A. Kappes, D. Kappesser, L. Kardum, T. Karg, M. Karl, A. Karle, U. Katz, M. Kauer, J. L. Kelley, A. Khatee Zathul, A. Kheirandish, J. Kiryluk, S. R. Klein, A. Kochocki, R. Koirala, H. Kolanoski, T. Kontrimas, L. Köpke, C. Kopper, D. J. Koskinen, P. Koundal, M. Kovacevich, M. Kowalski, T. Kozynets, K. Kruiswijk, E. Krupczak, A. Kumar, E. Kun, N. Kurahashi, N. Lad, C. Lagunas Gualda, M. Lamoureux, M. J. Larson, F. Lauber, J. P. Lazar, J. W. Lee, K. Leonard DeHolton, A. Leszczyńska, M. Lincetto, Q. R. Liu, M. Liubarska, E. Lohfink, C. Love, C. J. Lozano Mariscal, L. Lu, F. Lucarelli, A. Ludwig, W. Luszczak, Y. Lyu, J. Madsen, K. B. M. Mahn, Y. Makino, E. Manao, S. Mancina, W. Marie Sainte, I. C. Mariş, S. Marka, Z. Marka, M. Marsee, I. Martinez-Soler, R. Maruyama, F. Mayhew, T. McElroy, F. McNally, J. V. Mead, K. Meagher, S. Mechbal, A. Medina, M. Meier, Y. Merckx, L. Merten, J. Micallef, T. Montaruli, R. W. Moore, Y. Morii, R. Morse, M. Moulai, T. Mukherjee, R. Naab, R. Nagai, M. Nakos, U. Naumann, J. Necker, M. Neumann, H. Niederhausen, M. U. Nisa, A. Noell, S. C. Nowicki, A. Obertacke Pollmann, V. O'Dell, M. Oehler, B. Oeyen, A. Olivas, R. Orsoe, J. Osborn, E. O'Sullivan, H. Pandya, N. Park, G. K. Parker, E. N. Paudel, L. Paul, C. Pérez de los Heros, J. Peterson, S. Philippen, S. Pieper, A. Pizzuto, M. Plum, A. Pontén, Y. Popovych, M. Prado Rodriguez, B. Pries, R. Procter-Murphy, G. T. Przybylski, J. Rack-Helleis, K. Rawlins, Z. Rechav, A. Rehman, P. Reichherzer, G. Renzi, E. Resconi, S. Reusch, W. Rhode, M. Richman, B. Riedel, E. J. Roberts, S. Robertson, S. Rodan, G. Roellinghoff, M. Rongen, C. Rott, T. Ruhe, L. Ruohan, D. Ryckbosch, I. Safa, J. Saffer, D. Salazar-Gallegos, P. Sampathkumar, S. E. Sanchez Herrera, A. Sandrock, M. Santander, S. Sarkar, S. Sarkar, J. Savelberg, P. Savina, M. Schaufel, H. Schieler, S. Schindler, B. Schlüter, F. Schlüter, T. Schmidt, J. Schneider, F. G. Schröder, L. Schumacher, G. Schwefer, S. Sclafani, D. Seckel, S. Seunarine, R. Shah, A. Sharma, S. Shefali, N. Shimizu, M. Silva, B. Skrzypek, B. Smithers, R. Snihur, J. Soedingrekso, A. Søgaard, D. Soldin, G. Sommani, C. Spannfellner, G. M. Spiczak, C. Spiering, M. Stamatikos, T. Stanev, T. Stezelberger, T. Stürwald, T. Stuttard, G. W. Sullivan, I. Taboada, S. Ter-Antonyan, M. Thiesmeyer, W. G. Thompson, J. Thwaites, S. Tilav, K. Tollefson, C. Tönnis, S. Toscano, D. Tosi, A. Trettin, C. F. Tung, R. Turcotte, J. P. Twagirayezu, B. Ty, M. A. Unland Elorrieta, A. K. Upadhyay, K. Upshaw, N. Valtonen-Mattila, J. Vandenbroucke, N. van Eijndhoven, D. Vannerom, J. van Santen, J. Vara, J. Veitch-Michaelis, M. Venugopal, S. Verpoest, D. Veske, C. Walck, T. B. Watson, C. Weaver, P. Weigel, A. Weindl, J. Weldert, C. Wendt, J. Werthebach, M. Weyrauch, N. Whitehorn, C. H. Wiebusch, N. Willey, D. R. Williams, A. Wolf, M. Wolf, G. Wrede, X. W. Xu, J. P. Yanez, E. Yildizci, S. Yoshida, F. Yu, S. Yu, T. Yuan, Z. Zhang, and P. Zhelnin [hide authors].
We present a catalog of likely astrophysical neutrino track-like events from
the IceCube Neutrino Observatory. IceCube began reporting likely astrophysical
neutrinos in 2016 and this system was updated in 2019. The catalog presented
here includes events that were reported in real-time since 2019, as well as
events identified in archival data samples starting from 2011. We report 275
neutrino events from two selection channels as the first entries in the
catalog, the IceCube Event Catalog of Alert Tracks, which will see ongoing
extensions with additional alerts. The gold and bronze alert channels
respectively provide neutrino candidates with 50\% and 30\% probability of
being astrophysical, on average assuming an astrophysical neutrino power law
energy spectral index of 2.19. For each neutrino alert, we provide the
reconstructed energy, direction, false alarm rate, probability of being
astrophysical in origin, and likelihood contours describing the spatial
uncertainty in the alert's reconstructed location. We also investigate a
directional correlation of these neutrino events with gamma-ray and X-ray
catalogs including 4FGL, 3HWC, TeVCat and Swift-BAT.
March 2023
- Hermitian Matrix Diagonalization and its Symmetry Properties
2303.17087 [abs] [pdf]
[abstract]
by S. H. Chiu and T. K. Kuo.
A hermitian matrix can be parametrized by a set consisting of its determinant
and the eigenvalues of its submatrices. We established a group of equations
which connect these variables with the mixing parameters of diagonalization.
These equations are simple in structure and manifestly invariant in form under
the symmetry operations of dilatation, translation, rephasing and permutation.
When applied to the problem of neutrino oscillation in matter they produced two
new ``matter invariants" which are confirmed by available data.
- Remote Reactor Ranging via Antineutrino Oscillations
2303.16661 [abs] [pdf]
[abstract]
by Steve T. Wilson, [and 6 more]Chris Cotsford, James Armitage, Tara Appleyard, Niamh Holland, Matthew Malek, and John. G. Learned [hide authors].
Antineutrinos from nuclear reactors can be used for monitoring in the mid- to
far-field as part of a non-proliferation toolkit. Antineutrinos are an
unshieldable signal and carry information about the reactor core and the
distance they travel.
Using gadolinium-doped water Cherenkov detectors for this purpose has been
previously proposed alongside rate-only analyses. As antineutrinos carry
information about their distance of travel in their energy spectrum, the
analyses can be extended to a spectral analysis to gain more knowledge about
the detected core.
Two complementary analyses are used to evaluate the distance between a
proposed gadolinium-doped water-based liquid scintillator detector and a
detected nuclear reactor. Example cases are shown for a detector in Boulby
Mine, near the Boulby Underground Laboratory in the UK, and six reactor sites
in the UK and France. The analyses both show strong potential to range
reactors, but are limited by the detector design.
- Update on the indication of a mass-dependent anisotropy above
$10^{18.7}\,$eV in the hybrid data of the Pierre Auger Observatory
2303.16336 [abs] [pdf]
[abstract]
by Eric Mayotte and Thomas Fitoussi.
We test for an anisotropy in the mass of arriving cosmic-ray primaries
associated with the galactic plane. The sensitivity to primary mass is obtained
through the depth of shower maximum, $X_{\rm max}$, extracted from hybrid
events measured over a 14-year period at the Pierre Auger Observatory. The sky
is split into distinct on- and off-plane regions using the galactic latitude of
each arriving cosmic ray to form two distributions of $X_{\rm max}$, which are
compared using an Anderson-Darling 2-samples test. A scan over roughly half of
the data is used to select a lower threshold energy of $10^{18.7}\,$eV and a
galactic latitude splitting at $|b| = 30^\circ$, which are set as a
prescription for the remaining data. With these thresholds, the distribution of
$X_{\rm max}$ from the on-plane region is found to have a $9.1 \pm
1.6^{+2.1}_{-2.2}\,$g$\,$cm$^-2$ shallower mean and a
$5.9\pm2.1^{+3.5}_{-2.5}\,$g$\,$cm$^-2$ narrower width than that of the
off-plane region and is observed in all telescope sites independently. These
differences indicate that the mean mass of primary particles arriving from the
on-plane region is greater than that of those from the off-plane region. Monte
Carlo studies yield a $5.9\times10^{-6}$ random chance probability for the
result in the independent data, lowering to a $6.0\times10^{-7}$
post-penalization random chance probability when the scanned data is included.
Accounting for systematic uncertainties leads to an indication for anisotropy
in mass composition above $10^{18.7}\,$eV with a $3.3\,\sigma$ significance.
Furthermore, the result has been newly tested using additional FD data
recovered from the selection process. This test independently disfavors the on-
and off-plane regions being uniform in composition at the $2.2\,\sigma$ level,
which is in good agreement with the expected sensitivity of the dataset used
for this test.
- Relic Neutrino Helicity Evolution in Galactic Magnetic Field and Its
Implications
2303.15562 [abs] [pdf]
[abstract]
by Kuo K. Liao and Glennys R. Farrar.
We simulate the evolution of the helicity of relic neutrinos as they
propagate to Earth through a realistic model of the Galactic magnetic field,
improving upon the rough estimates in the pioneering work of Baym and Peng. We
find that with magnetic moments consistent with experimental bounds and even
several orders of magnitude smaller, the helicity of relic neutrinos rotates
with a substantial directional anisotropy. Averaged over directions this would
simply reduce the apparent flux; if the direction of the incident neutrino
could be measured, the directional anisotropy in the interaction probability
could become a powerful diagnostic. We study the effects of $\nu$ spin rotation
on C$\nu$B detection through the inverse tritium decay process.
- PEANUTS: a software for the automatic computation of solar neutrino flux
and its propagation within Earth
2303.15527 [abs] [pdf]
[abstract]
by Tomás E. Gonzalo and Michele Lucente.
We present PEANUTS (Propagation and Evolution of Active NeUTrinoS), an
open-source Python package for the automatic computation of solar neutrino
spectra and active neutrino propagation through Earth. PEANUTS is designed to
be fast, by employing analytic formulae for the neutrino propagation through
varying matter density, and flexible, by allowing the user to input arbitrary
solar models, custom Earth density profiles and general detector locations. It
provides functionalities for a fully automated simulation of solar neutrino
fluxes at a detector, as well as access to individual routines to perform more
specialised computations. The software has been extensively tested against the
results of the SNO experiment, providing excellent agreement with their
results. In addition, the present text contains a pedagogical derivation of the
relations needed to compute the oscillated solar neutrino spectra, neutrino
propagation through Earth and nadir exposure of an experiment.
- Decoherence effects in reactor and Gallium neutrino oscillation
experiments -- a QFT approach
2303.15524 [abs] [pdf]
[abstract]
by Raphael Krueger and Thomas Schwetz.
We adopt the quantum field theoretical method to calculate the amplitude and
event rate for a neutrino oscillation experiment, considering neutrino
production, propagation and detection as a single process. This method allows
to take into account decoherence effects in the transition amplitude induced by
the quantum mechanical uncertainties of all particles involved in the process.
We extend the method to include coherence loss due to interactions with the
environment, similar to collisional line broadening. In addition to generic
decoherence induced at the amplitude level, the formalism allows to include, in
a straightforward way, additional damping effects related to phase-space
integrals over momenta of unobserved particles as well as other classical
averaging effects. We apply this method to neutrino oscillation searches at
reactor and Gallium experiments and confirm that quantum decoherence is many
orders of magnitudes smaller than classical averaging effects and therefore
unobservable. The method used here can be applied with minimal modifications
also to other types of oscillation experiments, e.g., accelerator based beam
experiments.
- First Direct Observation of Collider Neutrinos with FASER at the LHC
2303.14185 [abs] [pdf]
[abstract]
by FASER Collaboration, [and 87 more]Henso Abreu, John Anders, Claire Antel, Akitaka Ariga, Tomoko Ariga, Jeremy Atkinson, Florian U. Bernlochner, Tobias Blesgen, Tobias Boeckh, Jamie Boyd, Lydia Brenner, Franck Cadoux, David W. Casper, Charlotte Cavanagh, Xin Chen, Andrea Coccaro, Ansh Desai, Sergey Dmitrievsky, Monica D'Onofrio, Yannick Favre, Deion Fellers, Jonathan L. Feng, Carlo Alberto Fenoglio, Didier Ferrere, Stephen Gibson, Sergio Gonzalez-Sevilla, Yuri Gornushkin, Carl Gwilliam, Daiki Hayakawa, Shih-Chieh Hsu, Zhen Hu, Giuseppe Iacobucci, Tomohiro Inada, Sune Jakobsen, Hans Joos, Enrique Kajomovitz, Hiroaki Kawahara, Alex Keyken, Felix Kling, Daniela Köck, Umut Kose, Rafaella Kotitsa, Susanne Kuehn, Helena Lefebvre, Lorne Levinson, Ke Li, Jinfeng Liu, Jack MacDonald, Chiara Magliocca, Fulvio Martinelli, Josh McFayden, Matteo Milanesio, Dimitar Mladenov, Théo Moretti, Magdalena Munker, Mitsuhiro Nakamura, Toshiyuki Nakano, Marzio Nessi, Friedemann Neuhaus, Laurie Nevay, Hidetoshi Otono, Hao Pang, Lorenzo Paolozzi, Brian Petersen, Francesco Pietropaolo, Markus Prim, Michaela Queitsch-Maitland, Filippo Resnati, Hiroki Rokujo, Elisa Ruiz-Choliz, Jorge Sabater-Iglesias, Osamu Sato, Paola Scampoli, Kristof Schmieden, Matthias Schott, Anna Sfyrla, Savannah Shively, Yosuke Takubo, Noshin Tarannum, Ondrej Theiner, Eric Torrence, Serhan Tufanli, Svetlana Vasina, Benedikt Vormwald, Di Wang, Eli Welch, and Stefano Zambito [hide authors].
We report the first direct observation of neutrino interactions at a particle
collider experiment. Neutrino candidate events are identified in a 13.6 TeV
center-of-mass energy $pp$ collision data set of 35.4 fb${}^{-1}$ using the
active electronic components of the FASER detector at the Large Hadron
Collider. The candidates are required to have a track propagating through the
entire length of the FASER detector and be consistent with a muon neutrino
charged-current interaction. We infer $153^{+12}_{-13}$ neutrino interactions
with a significance of 16 standard deviations above the background-only
hypothesis. These events are consistent with the characteristics expected from
neutrino interactions in terms of secondary particle production and spatial
distribution, and they imply the observation of both neutrinos and
anti-neutrinos with an incident neutrino energy of significantly above 200 GeV.
- Inferring astrophysical neutrino sources from the Glashow resonance
2303.13706 [abs] [pdf]
[abstract]
by Guo-yuan Huang, Manfred Lindner, and Nele Volmer.
We infer the ultrahigh energy neutrino source by using the Glashow resonance
candidate event recently identified by the IceCube Observatory. For the
calculation of the cross section for the Glashow resonance, we incorporate both
the atomic Doppler broadening effect and initial state radiation
$\overline{\nu}^{}_{e} e^- \to W^- \gamma$, which correct the original cross
section considerably. Using available experimental information, we have set a
generic constraint on the $\overline{\nu}^{}_{e}$ fraction of astrophysical
neutrinos, which excludes the $\mu$-damped ${\rm p}\gamma$ source around
$2\sigma$ confidence level. While a weak preference has been found for the pp
source, next-generation measurements will be able to distinguish between ideal
pp and p$\gamma$ sources with a high significance assuming an optimistic single
power-law neutrino spectrum.
- The Gallium Neutrino Absorption Cross Section and its Uncertainty
2303.13623 [abs] [pdf]
[abstract]
by S. R. Elliott, [and 4 more]V. N. Gavrin, W. C. Haxton, T. V. Ibragimova, and E. J. Rule [hide authors].
In the recent Baksan Experiment on Sterile Transitions (BEST), a suppressed
rate of neutrino absorption on a gallium target was observed, consistent with
earlier results from neutrino source calibrations of the SAGE and GALLEX/GNO
solar neutrino experiments. The BEST collaboration, utilizing a 3.4 MCi 51Cr
neutrino source, found observed-to-expected counting rates at two very short
baselines of R=0.791 plus/minus 0.05 and 0.766 plus/minus 0.05, respectively.
Among recent neutrino experiments, BEST is notable for the simplicity of both
its neutrino spectrum, line neutrinos from an electron-capture source whose
intensity can be measured to a estimated precision of 0.23%, and its absorption
cross section, where the precisely known rate of electron capture to the
gallium ground state, 71Ge(e,nue)71Ga(g.s.), establishes a minimum value.
However, the absorption cross section uncertainty is a common systematic in the
BEST, SAGE, and GALLEX/GNO neutrino source experiments. Here we update that
cross section, considering a variety of electroweak corrections and the role of
transitions to excited states, to establish both a central value and reasonable
uncertainty, thereby enabling a more accurate assessment of the statistical
significance of the gallium anomalies. Results are given for 51Cr and 37Ar
sources. The revised neutrino capture rates are used in a re-evaluation of the
BEST and gallium anomalies.
- High-energy neutrino deeply inelastic scattering cross sections from 100
GeV to 1000 EeV
2303.13607 [abs] [pdf]
[abstract]
by Keping Xie, [and 4 more]Jun Gao, T. J. Hobbs, Daniel R. Stump, and C. -P. Yuan [hide authors].
We present a state-of-the-art prediction for cross sections of neutrino
deeply inelastic scattering (DIS) from nucleon at high neutrino energies,
$E_\nu$, from 100 GeV to 1000 EeV ($10^{12}$ GeV). Our calculations are based
on the latest CT18 NNLO parton distribution functions (PDFs) and their
associated uncertainties. In order to make predictions for the highest
energies, we extrapolate the PDFs to small $x$ according to several procedures
and assumptions, thus affecting the uncertainties at ultra-high $E_\nu$; we
quantify the uncertainties corresponding to these choices. Similarly, we
quantify the uncertainties introduced by the nuclear corrections which are
required to evaluate neutrino-nuclear cross sections for neutrino telescopes.
These results can be applied to currently-running astrophysical neutrino
observatories, such as IceCube, as well as various future experiments which
have been proposed.
- Hunting for Neutral Leptons with Ultra-High-Energy Cosmic Rays
2303.11352 [abs] [pdf]
[abstract]
by Robert Heighton, Lucien Heurtier, and Michael Spannowsky.
Next-generation large-volume detectors, such as GRAND, POEMMA, Trinity,
TAROGE-M, TAMBO, or PUEO, have been designed to search for ultra-high-energy
cosmic rays (UHECRs) with unprecedented sensitivity. We propose to use these
detectors to search for new physics beyond the Standard Model (BSM). By
considering the simple case of a right-handed neutrino that mixes exclusively
with the active $\tau$ neutrino, we demonstrate that the existence of new
physics can increase the probability for UHECRs to propagate through the Earth
and produce extensive air showers that will be measurable soon. We compare the
fluxes of such showers that would arise from various diffuse and transient
sources of high-energy neutrinos, both in the Standard Model and in the
presence of a right-handed neutrino. We show that detecting events with
emergence angles $\gtrsim 10$ deg is promising to probe the existence of BSM
physics, and we study the sensitivity of GRAND and POEMMA to do so. In
particular, we show that the hypothesis of a right-handed neutrino with a mass
of $\mathcal O(1-16)$ GeV may be probed in the future for mixing angles as
small as $|U_{\tau N}|^2 \gtrsim 10^{-7}$, thus competing with existing and
projected experimental limits.
- An importance sampling method for Feldman-Cousins confidence intervals
2303.11290 [abs] [pdf]
[abstract]
by Lukas Berns.
In various high-energy physics contexts, such as neutrino-oscillation
experiments, several assumptions underlying the typical asymptotic confidence
interval construction are violated, such that one has to resort to
computationally expensive methods like the Feldman-Cousins method for obtaining
confidence intervals with proper statistical coverage. By construction, the
computation of intervals at high confidence levels requires fitting millions or
billions of pseudo-experiments, while wasting most of the computational cost on
overly precise intervals at low confidence levels. In this work, a simple
importance sampling method is introduced which reuses pseudo-experiments
produced for all tested parameter values in a single mixture distribution. This
results in a significant error reduction on the estimated critical values,
especially at high confidence levels, and simultaneously yields a correct
interpolation of these critical values between the parameter values at which
the pseudo-experiments were produced. The theoretically calculated performance
is demonstrated numerically using a simple example from the analysis of
neutrino oscillations. The relationship to similar techniques applied in
statistical mechanics and $p$-value computations is discussed.
- Impact of nuclear matrix element calculations for current and future
neutrinoless double beta decay searches
2303.10562 [abs] [pdf]
[abstract]
by Federica Pompa, Thomas Schwetz, and Jing-Yu Zhu.
Nuclear matrix elements (NME) are a crucial input for the interpretation of
neutrinoless double beta decay data. We consider a representative set of recent
NME calculations from different methods and investigate the impact on the
present bound on the effective Majorana mass $m_{\beta\beta}$ by performing a
combined analysis of the available data as well as on the sensitivity reach of
future projects. A crucial role is played by the recently discovered
short-range contribution to the NME, induced by light Majorana neutrino masses.
Depending on the NME model and the relative sign of the long- and short-range
contributions, the current $3\sigma$ bound can change between $m_{\beta\beta} <
40$ meV and 600 meV. The sign-uncertainty may either boost the sensitivity of
next-generation experiments beyond the region for $m_{\beta\beta}$ predicted
for inverted mass ordering or prevent even advanced setups to reach this
region. Furthermore, we study the possibility to distinguish between different
NME calculations by assuming a positive signal and by combining measurements
from different isotopes. Such a discrimination will be impossible if the
relative sign of the long- and short-range contribution remains unknown, but
can become feasible if $m_{\beta\beta} \gtrsim 40$ meV and if the relative sign
is known to be positive. Sensitivities will be dominated by the advanced
$^{76}$Ge and $^{136}$Xe setups assumed here, but NME model-discrimination
improves if data from a third isotope is added, e.g., from $^{130}$Te or
$^{100}$Mo.
- Reconstructing Galactic magnetic fields from local measurements for
backtracking ultra-high-energy cosmic rays
2303.10099 [abs] [pdf]
[abstract]
by Alexandros Tsouros, [and 4 more]Gordian Edenhofer, Torsten Enßlin, Michalis Mastorakis, and Vasiliki Pavlidou [hide authors].
(abridged) Ultra-high energy cosmic rays (UHECRs) are highly energetic
charged particles with energies exceeding $10^{18}$ eV. Identifying their
sources and production mechanism can provide insight into many open questions
in astrophysics and high energy physics. However, the Galactic magnetic field
(GMF) deflects UHECRs, and the high uncertainties in our current understanding
of the $3$-dimensional structure of the GMF does not permit us to accurately
determine their true arrival direction on the plane of the sky (PoS). This
difficulty arises from the fact that currently all GMF observations are
integrated along the line-of-sight (LoS). Upcoming stellar optopolarimetric
surveys as well as Gaia data on stellar parallaxes, are expected to provide
local measurements of the GMF in the near future. In this paper, we evaluate
the reconstruction of the GMF in a limited region of the Galaxy given sparse
and local GMF measurements within that region, through Bayesian inference using
principles of Information Field Theory. We backtrack UHECRs through GMF
configurations drawn from the posterior to improve our knowledge of their true
arrival directions. We show that, for a weakly turbulent GMF, it is possible to
correct for its effect on the observed arrival direction of UHECRs to within
$\sim 3^\circ$. For completely turbulent fields, we show that our procedure can
still be used to significantly improve our knowledge on the true arrival
direction of UHECRs.
- Earth tomography with supernova neutrinos at future neutrino detectors
2303.09369 [abs] [pdf]
[abstract]
by Rasmi Hajjar, Olga Mena, and Sergio Palomares-Ruiz.
Earth neutrino tomography is a realistic possibility with current and future
neutrino detectors, complementary to geophysics methods. The two main
approaches are based on either partial absorption of the neutrino flux as it
propagates through the Earth (at energies about a few TeV) or on coherent Earth
matter effects affecting the neutrino oscillations pattern (at energies below a
few tens of GeV). In this work, we consider the latter approach focusing on
supernova neutrinos with tens of MeV. Whereas at GeV energies, Earth matter
effects are driven by the atmospheric mass-squared difference, at energies
below $\sim 100$~MeV, it is the solar mass-squared difference what controls
them. Unlike solar neutrinos, which suffer from significant weakening of the
contribution to the oscillatory effect from remote structures due to the
neutrino energy reconstruction capabilities of detectors, supernova neutrinos
can have higher energies and thus, can better probe the Earth's interior. We
shall revisit this possibility, using the most recent neutrino oscillation
parameters and up-to-date supernova neutrino spectra. The capabilities of
future neutrino detectors, such as DUNE, Hyper-Kamiokande and JUNO are
presented, including the impact of the energy resolution and other factors.
Assuming a supernova burst at 10~kpc, we show that the average Earth's core
density could be determined within $\lesssim 10\%$ at $1\sigma$ confidence
level, being Hyper-Kamiokande, with its largest mass, the most promising
detector to achieve this goal.
- Nuclear neutron radius and weak mixing angle measurements from latest
COHERENT CsI and atomic parity violation Cs data
2303.09360 [abs] [pdf]
[abstract]
by M. Atzori Corona, [and 5 more]M. Cadeddu, N. Cargioli, F. Dordei, C. Giunti, and G. Masia [hide authors].
The COHERENT collaboration observed coherent elastic neutrino nucleus
scattering using a 14.6 kg cesium-iodide (CsI) detector in 2017 and recently
published the updated results before decommissioning the detector. Here, we
present the legacy determination of the weak mixing angle and of the average
neutron rms radius of $^{133}\mathrm{Cs}$ and $^{127}\mathrm{I}$ obtained with
the full CsI dataset, also exploiting the combination with the atomic parity
violation (APV) experimental result, that allows us to achieve a precision as
low as $\sim$4.5% and to disentangle the contributions of the
$^{133}\mathrm{Cs}$ and $^{127}\mathrm{I}$ nuclei. Interestingly, we show that
the COHERENT CsI data show a 6$\sigma$ evidence of the nuclear structure
suppression of the full coherence. Moreover, we derive a data-driven
APV+COHERENT measurement of the low-energy weak mixing angle with a percent
uncertainty, independent of the value of the average neutron rms radius of
$^{133}\mathrm{Cs}$ and $^{127}\mathrm{I}$, that is allowed to vary freely in
the fit. Additionally, we extensively discuss the impact of using two different
determinations of the theoretical parity non-conserving amplitude in the APV
fit. Our findings show that the particular choice can make a significant
difference, up to 6.5% on $R_n$(Cs) and 11% on the weak mixing angle. Finally,
in light of the recent announcement of a future deployment of a 10 kg and a
$\sim$700 kg cryogenic CsI detectors, we provide future prospects for these
measurements, comparing them with other competitive experiments that are
foreseen in the near future.
- Modification of the Dipole in Arrival Directions of Ultra-high-energy
Cosmic Rays due to the Galactic Magnetic Field
2303.08766 [abs] [pdf]
[abstract]
by Alena Bakalová, Jakub Vícha, and Petr Trávníček.
The direction and magnitude of the dipole anisotropy of ultra-high-energy
cosmic rays with energies above 8 EeV observed by the Pierre Auger Observatory
indicate their extragalactic origin. The observed dipole on Earth does not
necessarily need to correspond to the anisotropy of the extragalactic
cosmic-ray flux due to the effects of propagation in the Galactic magnetic
field. We estimate the size of these effects via numerical simulations using
the CRPropa 3 package. The Jansson-Farrar and Terral-Ferri\`ere models of the
Galactic magnetic field are used to propagate particles from the edge of the
Galaxy to an observer on Earth. We identify allowed directions and amplitudes
of the dipole outside the Galaxy that are compatible with the measured features
of the dipole on Earth for various mass composition scenarios at the 68% and
95% confidence level.
- Tau Polarization and Correlated Decays in Neutrino Experiments
2303.08104 [abs] [pdf]
[abstract]
by Joshua Isaacson, [and 3 more]Stefan Höche, Frank Siegert, and Sherry Wang [hide authors].
We present the first fully differential predictions for tau neutrino
scattering in the energy region relevant to the DUNE experiment, including all
spin correlations and all tau lepton decay channels. The calculation is
performed using a generic interface between the neutrino event generator
Achilles and the publicly available, general-purpose collider event simulation
framework Sherpa.
- Towards Resolving the Gallium Anomaly
2303.05528 [abs] [pdf]
[abstract]
by Vedran Brdar, Julia Gehrlein, and Joachim Kopp.
A series of experiments studying neutrinos from intense radioactive sources
have reported a deficit in the measured event rate which, in combination, has
reached a statistical significance of $\sim 5\sigma$. In this paper, we explore
avenues for explaining this anomaly, both within the Standard Model and beyond.
First, we discuss possible biases in the predicted cross section for the
detection reaction $\nu_e + ^{71}\text{Ga} \to e^- + ^{71}\text{Ge}$, which
could arise from mismeasurement of the inverse process, $^{71}\text{Ge}$ decay,
or from the presence of as yet unknown low-lying excited states of
$^{71}\text{Ga}$. The latter would imply that not all $^{71}\text{Ge}$ decays
go to the ground state of $^{71}\text{Ga}$, so the extraction of the ground
state-to-ground state matrix element relevant for neutrino capture on gallium
would be incorrect. Second, we scrutinize the measurement of the source
intensity in gallium experiments, and we point out that a $\sim 2\%$ error in
the branching ratios for $^{51}\text{Cr}$ decay would be enough to explain the
anomaly. Third, we investigate the calibration of the radiochemical germanium
extraction efficiency as a possible origin of anomaly. Finally, we outline
several new explanations beyond the Standard Model, including scenarios with
sterile neutrinos coupled to fuzzy dark matter or to dark energy, as well as a
model with decaying sterile neutrinos. We critically assess the viability of
these scenarios, and others that have been proposed, in a summary table.
- Observation of Seasonal Variations of the Flux of High-Energy
Atmospheric Neutrinos with IceCube
2303.04682 [abs] [pdf]
[abstract]
by R. Abbasi, [and 393 more]M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, V. Basu, R. Bay, J. J. Beatty, K. -H. Becker, J. Becker Tjus, J. Beise, C. Bellenghi, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, G. Binder, D. Bindig, E. Blaufuss, S. Blot, F. Bontempo, J. Y. Book, C. Boscolo Meneguolo, S. Böser, O. Botner, J. Böttcher, E. Bourbeau, J. Braun, B. Brinson, J. Brostean-Kaiser, R. T. Burley, R. S. Busse, D. Butterfield, M. A. Campana, K. Carloni, E. G. Carnie-Bronca, S. Chattopadhyay, C. Chen, Z. Chen, D. Chirkin, S. Choi, B. A. Clark, L. Classen, A. Coleman, G. H. Collin, A. Connolly, J. M. Conrad, P. Coppin, P. Correa, S. Countryman, D. F. Cowen, P. Dave, C. De Clercq, J. J. DeLaunay, D. Delgado López, H. Dembinski, S. Deng, K. Deoskar, A. Desai, P. Desiati, K. D. de Vries, G. de Wasseige, T. DeYoung, A. Diaz, J. C. Díaz-Vélez, M. Dittmer, A. Domi, H. Dujmovic, M. A. DuVernois, T. Ehrhardt, P. Eller, R. Engel, H. Erpenbeck, J. Evans, P. A. Evenson, K. L. Fan, K. Fang, A. R. Fazely, A. Fedynitch, N. Feigl, S. Fiedlschuster, C. Finley, L. Fischer, D. Fox, A. Franckowiak, E. Friedman, A. Fritz, P. Fürst, T. K. Gaisser, J. Gallagher, E. Ganster, A. Garcia, S. Garrappa, L. Gerhardt, A. Ghadimi, C. Glaser, T. Glauch, T. Glüsenkamp, N. Goehlke, J. G. Gonzalez, S. Goswami, D. Grant, S. J. Gray, S. Griffin, S. Griswold, C. Günther, P. Gutjahr, C. Haack, A. Hallgren, R. Halliday, L. Halve, F. Halzen, H. Hamdaoui, M. Ha Minh, K. Hanson, J. Hardin, A. A. Harnisch, P. Hatch, A. Haungs, S. Hauser, K. Helbing, J. Hellrung, F. Henningsen, L. Heuermann, S. Hickford, A. Hidvegi, C. Hill, G. C. Hill, K. D. Hoffman, K. Hoshina, W. Hou, T. Huber, K. Hultqvist, M. Hünnefeld, R. Hussain, K. Hymon, S. In, N. Iovine, A. Ishihara, M. Jacquart, M. Jansson, G. S. Japaridze, K. Jayakumar, M. Jeong, M. Jin, B. J. P. Jones, D. Kang, W. Kang, X. Kang, A. Kappes, D. Kappesser, L. Kardum, T. Karg, M. Karl, A. Karle, U. Katz, M. Kauer, J. L. Kelley, A. Khatee Zathul, A. Kheirandish, K. Kin, J. Kiryluk, S. R. Klein, A. Kochocki, R. Koirala, H. Kolanoski, T. Kontrimas, L. Köpke, C. Kopper, D. J. Koskinen, P. Koundal, M. Kovacevich, M. Kowalski, T. Kozynets, K. Kruiswijk, E. Krupczak, A. Kumar, E. Kun, N. Kurahashi, N. Lad, C. Lagunas Gualda, M. Lamoureux, M. J. Larson, F. Lauber, J. P. Lazar, J. W. Lee, K. Leonard DeHolton, A. Leszczyńska, M. Lincetto, Q. R. Liu, M. Liubarska, E. Lohfink, C. Love, C. J. Lozano Mariscal, L. Lu, F. Lucarelli, A. Ludwig, W. Luszczak, Y. Lyu, W. Y. Ma, J. Madsen, K. B. M. Mahn, Y. Makino, S. Mancina, W. Marie Sainte, I. C. Mariş, S. Marka, Z. Marka, M. Marsee, I. Martinez-Soler, R. Maruyama, F. Mayhew, T. McElroy, F. McNally, J. V. Mead, K. Meagher, S. Mechbal, A. Medina, M. Meier, S. Meighen-Berger, Y. Merckx, L. Merten, J. Micallef, D. Mockler, T. Montaruli, R. W. Moore, Y. Morii, R. Morse, M. Moulai, T. Mukherjee, R. Naab, R. Nagai, M. Nakos, U. Naumann, J. Necker, M. Neumann, H. Niederhausen, M. U. Nisa, A. Noell, S. C. Nowicki, A. Obertacke Pollmann, M. Oehler, B. Oeyen, A. Olivas, R. Orsoe, J. Osborn, E. O'Sullivan, H. Pandya, N. Park, G. K. Parker, E. N. Paudel, L. Paul, C. Pérez de los Heros, J. Peterson, S. Philippen, S. Pieper, A. Pizzuto, M. Plum, Y. Popovych, M. Prado Rodriguez, B. Pries, R. Procter-Murphy, G. T. Przybylski, C. Raab, J. Rack-Helleis, K. Rawlins, Z. Rechav, A. Rehman, P. Reichherzer, G. Renzi, E. Resconi, S. Reusch, W. Rhode, M. Richman, B. Riedel, E. J. Roberts, S. Robertson, S. Rodan, G. Roellinghoff, M. Rongen, C. Rott, T. Ruhe, L. Ruohan, D. Ryckbosch, S. Athanasiadou, I. Safa, J. Saffer, D. Salazar-Gallegos, P. Sampathkumar, S. E. Sanchez Herrera, A. Sandrock, M. Santander, S. Sarkar, S. Sarkar, J. Savelberg, P. Savina, M. Schaufel, H. Schieler, S. Schindler, B. Schlüter, T. Schmidt, J. Schneider, F. G. Schröder, L. Schumacher, G. Schwefer, S. Sclafani, D. Seckel, S. Seunarine, A. Sharma, S. Shefali, N. Shimizu, M. Silva, B. Skrzypek, B. Smithers, R. Snihur, J. Soedingrekso, A. Søgaard, D. Soldin, G. Sommani, C. Spannfellner, G. M. Spiczak, C. Spiering, M. Stamatikos, T. Stanev, R. Stein, T. Stezelberger, T. Stürwald, T. Stuttard, G. W. Sullivan, I. Taboada, S. Ter-Antonyan, W. G. Thompson, J. Thwaites, S. Tilav, K. Tollefson, C. Tönnis, S. Toscano, D. Tosi, A. Trettin, C. F. Tung, R. Turcotte, J. P. Twagirayezu, B. Ty, M. A. Unland Elorrieta, A. K. Upadhyay, K. Upshaw, N. Valtonen-Mattila, J. Vandenbroucke, N. van Eijndhoven, D. Vannerom, J. van Santen, J. Vara, J. Veitch-Michaelis, M. Venugopal, S. Verpoest, D. Veske, C. Walck, T. B. Watson, C. Weaver, P. Weigel, A. Weindl, J. Weldert, C. Wendt, J. Werthebach, M. Weyrauch, N. Whitehorn, C. H. Wiebusch, N. Willey, D. R. Williams, M. Wolf, G. Wrede, J. Wulff, X. W. Xu, J. P. Yanez, E. Yildizci, S. Yoshida, F. Yu, S. Yu, T. Yuan, Z. Zhang, and P. Zhelnin [hide authors].
Atmospheric muon neutrinos are produced by meson decays in cosmic-ray-induced
air showers. The flux depends on meteorological quantities such as the air
temperature, which affects the density of air. Competition between decay and
re-interaction of those mesons in the first particle production generations
gives rise to a higher neutrino flux when the air density in the stratosphere
is lower, corresponding to a higher temperature. A measurement of a temperature
dependence of the atmospheric $\nu_{\mu}$ flux provides a novel method for
constraining hadro\-nic interaction models of air showers. It is particularly
sensitive to the production of kaons. Studying this temperature dependence for
the first time requires a large sample of high-energy neutrinos as well as a
detailed understanding of atmospheric properties. We report the significant ($>
10 \sigma$) observation of a correlation between the rate of more than 260,000
neutrinos, detected by IceCube between 2012 and 2018, and atmospheric
temperatures of the stratosphere, measured by the Atmospheric Infrared Sounder
(AIRS) instrument aboard NASA's AQUA satellite. For the observed 10$\%$
seasonal change of effective atmospheric temperature we measure a 3.5(3)$\%$
change in the muon neutrino flux. This observed correlation deviates by about
2-3 standard deviations from the expected correlation of 4.3$\%$ as obtained
from theoretical predictions under the assumption of various hadronic
interaction models
- Measurements of neutrino oscillation parameters from the T2K experiment
using $3.6\times10^{21}$ protons on target
2303.03222 [abs] [pdf]
[abstract]
by The T2K Collaboration, [and 400 more]K. Abe, N. Akhlaq, R. Akutsu, A. Ali, S. Alonso Monsalve, C. Alt, C. Andreopoulos, M. Antonova, S. Aoki, T. Arihara, Y. Asada, Y. Ashida, E. T. Atkin, M. Barbi, G. J. Barker, G. Barr, D. Barrow, M. Batkiewicz-Kwasniak, F. Bench, V. Berardi, L. Berns, S. Bhadra, A. Blanchet, A. Blondel, S. Bolognesi, T. Bonus, S. Bordoni, S. B. Boyd, A. Bravar, C. Bronner, S. Bron, A. Bubak, M. Buizza Avanzini, J. A. Caballero, N. F. Calabria, S. Cao, D. Carabadjac, A. J. Carter, S. L. Cartwright, M. G. Catanesi, A. Cervera, J. Chakrani, D. Cherdack, P. S. Chong, G. Christodoulou, A. Chvirova, M. Cicerchia, J. Coleman, G. Collazuol, L. Cook, A. Cudd, C. Dalmazzone, T. Daret, Yu. I. Davydov, A. De Roeck, G. De Rosa, T. Dealtry, C. C. Delogu, C. Densham, A. Dergacheva, F. Di Lodovico, S. Dolan, D. Douqa, T. A. Doyle, O. Drapier, J. Dumarchez, P. Dunne, K. Dygnarowicz, A. Eguchi, S. Emery-Schrenk, G. Erofeev, A. Ershova, G. Eurin, D. Fedorova, S. Fedotov, M. Feltre, A. J. Finch, G. A. Fiorentini Aguirre, G. Fiorillo, M. D. Fitton, J. M. Franco Patiño, M. Friend, Y. Fujii, Y. Fukuda, K. Fusshoeller, L. Giannessi, C. Giganti, V. Glagolev, M. Gonin, J. González Rosa, E. A. G. Goodman, A. Gorin, M. Grassi, M. Guigue, D. R. Hadley, J. T. Haigh, P. Hamacher-Baumann, D. A. Harris, M. Hartz, T. Hasegawa, S. Hassani, N. C. Hastings, Y. Hayato, D. Henaff, A. Hiramoto, M. Hogan, J. Holeczek, A. Holin, T. Holvey, N. T. Hong Van, T. Honjo, F. Iacob, A. K. Ichikawa, M. Ikeda, T. Ishida, M. Ishitsuka, H. T. Israel, K. Iwamoto, A. Izmaylov, N. Izumi, M. Jakkapu, B. Jamieson, S. J. Jenkins, C. Jesús-Valls, J. J. Jiang, P. Jonsson, S. Joshi, C. K. Jung, P. B. Jurj, M. Kabirnezhad, A. C. Kaboth, T. Kajita, H. Kakuno, J. Kameda, S. P. Kasetti, Y. Kataoka, Y. Katayama, T. Katori, M. Kawaue, E. Kearns, M. Khabibullin, A. Khotjantsev, T. Kikawa, H. Kikutani, S. King, V. Kiseeva, J. Kisiel, T. Kobata, H. Kobayashi, T. Kobayashi, L. Koch, S. Kodama, A. Konaka, L. L. Kormos, Y. Koshio, A. Kostin, T. Koto, K. Kowalik, Y. Kudenko, Y. Kudo, S. Kuribayashi, R. Kurjata, T. Kutter, M. Kuze, M. La Commara, L. Labarga, K. Lachner, J. Lagoda, S. M. Lakshmi, M. Lamers James, M. Lamoureux, A. Langella, J. -F. Laporte, D. Last, N. Latham, M. Laveder, L. Lavitola, M. Lawe, Y. Lee, C. Lin, S. -K. Lin, R. P. Litchfield, S. L. Liu, W. Li, A. Longhin, K. R. Long, A. Lopez Moreno, L. Ludovici, X. Lu, T. Lux, L. N. Machado, L. Magaletti, K. Mahn, M. Malek, M. Mandal, S. Manly, A. D. Marino, L. Marti-Magro, D. G. R. Martin, M. Martini, J. F. Martin, T. Maruyama, T. Matsubara, V. Matveev, C. Mauger, K. Mavrokoridis, E. Mazzucato, N. McCauley, J. McElwee, K. S. McFarland, C. McGrew, J. McKean, A. Mefodiev, G. D. Megias, P. Mehta, L. Mellet, C. Metelko, M. Mezzetto, E. Miller, A. Minamino, O. Mineev, S. Mine, M. Miura, L. Molina Bueno, S. Moriyama, S. Moriyama, P. Morrison, Th. A. Mueller, D. Munford, L. Munteanu, K. Nagai, Y. Nagai, T. Nakadaira, K. Nakagiri, M. Nakahata, Y. Nakajima, A. Nakamura, H. Nakamura, K. Nakamura, K. D. Nakamura, Y. Nakano, S. Nakayama, T. Nakaya, K. Nakayoshi, C. E. R. Naseby, T. V. Ngoc, V. Q. Nguyen, K. Niewczas, S. Nishimori, Y. Nishimura, K. Nishizaki, T. Nosek, F. Nova, P. Novella, J. C. Nugent, H. M. O'Keeffe, L. O'Sullivan, T. Odagawa, T. Ogawa, R. Okada, W. Okinaga, K. Okumura, T. Okusawa, N. Ospina, R. A. Owen, Y. Oyama, V. Palladino, V. Paolone, M. Pari, J. Parlone, S. Parsa, J. Pasternak, M. Pavin, D. Payne, G. C. Penn, D. Pershey, L. Pickering, C. Pidcott, G. Pintaudi, C. Pistillo, B. Popov, K. Porwit, M. Posiadala-Zezula, Y. S. Prabhu, F. Pupilli, B. Quilain, T. Radermacher, E. Radicioni, B. Radics, M. A. Ramírez, P. N. Ratoff, M. Reh, C. Riccio, E. Rondio, S. Roth, N. Roy, A. Rubbia, A. C. Ruggeri, C. A. Ruggles, A. Rychter, K. Sakashita, F. Sánchez, G. Santucci, C. M. Schloesser, K. Scholberg, M. Scott, Y. Seiya, T. Sekiguchi, H. Sekiya, D. Sgalaberna, A. Shaikhiev, F. Shaker, A. Shaykina, M. Shiozawa, W. Shorrock, A. Shvartsman, N. Skrobova, K. Skwarczynski, D. Smyczek, M. Smy, J. T. Sobczyk, H. Sobel, F. J. P. Soler, Y. Sonoda, A. J. Speers, R. Spina, I. A. Suslov, S. Suvorov, A. Suzuki, S. Y. Suzuki, Y. Suzuki, A. A. Sztuc, M. Tada, S. Tairafune, S. Takayasu, A. Takeda, Y. Takeuchi, K. Takifuji, H. K. Tanaka, Y. Tanihara, M. Tani, A. Teklu, V. V. Tereshchenko, N. Teshima, N. Thamm, L. F. Thompson, W. Toki, C. Touramanis, T. Towstego, K. M. Tsui, T. Tsukamoto, M. Tzanov, Y. Uchida, M. Vagins, D. Vargas, M. Varghese, G. Vasseur, C. Vilela, E. Villa, W. G. S. Vinning, U. Virginet, T. Vladisavljevic, T. Wachala, J. G. Walsh, Y. Wang, L. Wan, D. Wark, M. O. Wascko, A. Weber, R. Wendell, M. J. Wilking, C. Wilkinson, J. R. Wilson, K. Wood, C. Wret, J. Xia, Y. -h. Xu, K. Yamamoto, T. Yamamoto, C. Yanagisawa, G. Yang, T. Yano, K. Yasutome, N. Yershov, U. Yevarouskaya, M. Yokoyama, Y. Yoshimoto, N. Yoshimura, M. Yu, R. Zaki, A. Zalewska, J. Zalipska, K. Zaremba, G. Zarnecki, X. Zhao, T. Zhu, M. Ziembicki, E. D. Zimmerman, M. Zito, and S. Zsoldos [hide authors].
The T2K experiment presents new measurements of neutrino oscillation
parameters using $19.7(16.3)\times10^{20}$ protons on target (POT) in
(anti-)neutrino mode at the far detector (FD). Compared to the previous
analysis, an additional $4.7\times10^{20}$ POT neutrino data was collected at
the FD. Significant improvements were made to the analysis methodology, with
the near-detector analysis introducing new selections and using more than
double the data. Additionally, this is the first T2K oscillation analysis to
use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux
model, and the neutrino interaction model was improved to include new nuclear
effects and calculations. Frequentist and Bayesian analyses are presented,
including results on $\sin^2\theta_{13}$ and the impact of priors on the
$\delta_\mathrm{CP}$ measurement. Both analyses prefer the normal mass ordering
and upper octant of $\sin^2\theta_{23}$ with a nearly maximally CP-violating
phase. Assuming the normal ordering and using the constraint on
$\sin^2\theta_{13}$ from reactors, $\sin^2\theta_{23}=0.561^{+0.021}_{-0.032}$
using Feldman--Cousins corrected intervals, and
$\Delta{}m^2_{32}=2.494_{-0.058}^{+0.041}\times10^{-3}~\mathrm{eV^2}$ using
constant $\Delta\chi^{2}$ intervals. The CP-violating phase is constrained to
$\delta_\mathrm{CP}=-1.97_{-0.70}^{+0.97}$ using Feldman--Cousins corrected
intervals, and $\delta_\mathrm{CP}=0,\pi$ is excluded at more than 90%
confidence level. A Jarlskog invariant of zero is excluded at more than
$2\sigma$ credible level using a flat prior in $\delta_\mathrm{CP}$, and just
below $2\sigma$ using a flat prior in $\sin\delta_\mathrm{CP}$. When the
external constraint on $\sin^2\theta_{13}$ is removed,
$\sin^2\theta_{13}=28.0^{+2.8}_{-6.5}\times10^{-3}$, in agreement with
measurements from reactor experiments. These results are consistent with
previous T2K analyses.
February 2023
- Quantifying the tension between cosmological and terrestrial constraints
on neutrino masses
2302.14159 [abs] [pdf]
[abstract]
by Stefano Gariazzo, Olga Mena, and Thomas Schwetz.
The sensitivity of cosmology to the total neutrino mass scale $\Sigma m_\nu$
is approaching the minimal values required by oscillation data. We study
quantitatively possible tensions between current and forecasted cosmological
and terrestrial neutrino mass limits by applying suitable statistical tests
such as Bayesian suspiciousness, parameter goodness-of-fit tests, or a
parameter difference test. In particular, the tension will depend on whether
the normal or the inverted neutrino mass ordering is assumed. We argue, that it
makes sense to reject inverted ordering from the cosmology/oscillation
comparison only if data are consistent with normal ordering. Our results
indicate that, in order to reject inverted ordering with this argument, an
accuracy on the sum of neutrino masses $\sigma ({m_\nu})$ of better than
0.02~eV would be required from future cosmological observations.
- A Direct Detection View of the Neutrino NSI Landscape
2302.12846 [abs] [pdf]
[abstract]
by Dorian W. P. Amaral, [and 3 more]David Cerdeno, Andrew Cheek, and Patrick Foldenauer [hide authors].
In this article, we study the potential of direct detection experiments to
explore the parameter space of general non-standard neutrino interactions (NSI)
via solar neutrino scattering. Due to their sensitivity to neutrino-electron
and neutrino-nucleus scattering, direct detection provides a complementary view
of the NSI landscape to that of spallation sources and neutrino oscillation
experiments. In particular, the large admixture of tau neutrinos in the solar
flux makes direct detection experiments well-suited to probe the full flavour
space of NSI. To study this, we develop a re-parametrisation of the NSI
framework that explicitly includes a variable electron contribution and allows
for a clear visualisation of the complementarity of the different experimental
sources. Using this new parametrisation, we explore how previous bounds from
spallation source and neutrino oscillation experiments are impacted. For the
first time, we compute limits on NSI from the first results of the XENONnT and
LUX-ZEPLIN experiments, and we obtain projections for future xenon-based
experiments. These computations have been performed with our newly developed
software package, SNuDD. Our results demonstrate the importance of using a more
general NSI parametrisation and indicate that next generation direct detection
experiments will become powerful probes of neutrino NSI.
- Oscillation probabilities for a PT-symmetric non-Hermitian two-state
system
2302.11666 [abs] [pdf]
[abstract]
by Jean Alexandre, [and 4 more]Madeleine Dale, John Ellis, Robert Mason, and Peter Millington [hide authors].
There is growing interest in viable quantum theories with PT-symmetric
non-Hermitian Hamiltonians, but a formulation of transition matrix elements
consistent with positivity and perturbative unitarity has so far proved
elusive. This Letter provides such a formulation, which relies crucially on the
ability to span the state space in such a way that the interaction and energy
eigenstates are orthonormal with respect to the same positive-definite inner
product. We mention possible applications to the oscillations of mesons and
neutrinos.
- The Neutrino Magnetic Moment Portal and Supernovae: New Constraints and
Multimessenger Opportunities
2302.10965 [abs] [pdf]
[abstract]
by Vedran Brdar, [and 3 more]André de Gouvêa, Ying-Ying Li, and Pedro A. N. Machado [hide authors].
We scrutinize the hypothesis that gauge singlet fermions -- sterile neutrinos
-- interact with Standard Model particles through the transition magnetic
moment portal. These interactions lead to the production of sterile neutrinos
in supernovae followed by their decay into photons and active neutrinos which
can be detected at $\gamma$-ray telescopes and neutrino detectors,
respectively. We find that the non-observation of active neutrinos and photons
from sterile-neutrino decay associated to SN1987A yields the strongest
constraints to date on magnetic-moment-coupled sterile neutrinos if their
masses are inside a $0.1-100$ MeV window. Assuming a near-future galactic
supernova explosion, we estimate the sensitivity of several present and
near-future experiments, including Fermi-LAT, e-ASTROGAM, DUNE, and
Hyper-Kamiokande, to magnetic-moment-coupled sterile neutrinos. We also study
the diffuse photon and neutrino fluxes produced in the decay of magnetic-moment
coupled sterile neutrinos produced in all past supernova explosions and find
that the absence of these decay daughters yields the strongest constraints to
date for sterile neutrino masses inside a $1-100$ keV window.
- How to measure the reactor neutrino flux below the inverse beta decay
threshold with CE$ν$NS
2302.10460 [abs] [pdf]
[abstract]
by Jiajun Liao, Hongkai Liu, and Danny Marfatia.
Most antineutrinos produced in a nuclear reactor have energies below the
inverse beta decay threshold, and have not yet been detected. We show that a
coherent elastic neutrino-nucleus scattering experiment with an ultra-low
energy threshold like NUCLEUS can measure the flux of reactor neutrinos below
1.8 MeV. Using a regularized unfolding procedure, we find that a meaningful
upper bound can be placed on the low energy flux, but the existence of the
neutron capture component cannot be established.
- Investigating the effects of Lorentz Invariance Violation on the
CP-sensitivities of the Deep Underground Neutrino Experiment
2302.10456 [abs] [pdf]
[abstract]
by Arnab Sarker, Abinash Medhi, and Moon Moon Devi.
The neutrino oscillations offer great potential for probing new physics
effects beyond the Standard Model. Any additional effect on neutrino
oscillations can help understand the nature of these non-standard effects. The
violation of fundamental symmetries may appear as new physics effects in
various neutrino experiments. Lorentz symmetry is one such fundamental symmetry
in nature, the violation of which implies a breakdown of space-time symmetry.
The Lorentz Invariance Violation (LIV) is intrinsic in nature and its effects
exist even in a vacuum. Neutrinos can be an intriguing probe for exploring such
violations of Lorentz symmetry. The effect of violation of Lorentz Invariance
can be explored through the impact on the neutrino oscillation probabilities.
The effect of LIV is treated as a perturbation to the standard neutrino
Hamiltonian considering the Standard Model Extension (SME) framework. In this
work, we have probed the effect of LIV on the neutrino oscillation measurements
considering the Deep Underground Neutrino Experiment (DUNE) as a case study.
The inclusion of LIV affects various neutrino oscillation parameters as it
modifies the standard neutrino oscillation probabilities. We looked into the
capability of DUNE in constraining the LIV parameters and then explored the
impact of CPT-violating LIV terms on the mass-induced neutrino oscillation
probabilities. We have also probed the influence of LIV parameters on the
CP-measurement sensitivity at DUNE.
- On the Tremaine-Gunn Limit with Mass-Varying Particles
2302.10246 [abs] [pdf]
[abstract]
by Lotfi Boubekeur and Stefano Profumo.
General classical arguments on the time evolution of the phase-space density
can be used to derive constraints on the mass of particle candidates for the
cosmological dark matter (DM). The resulting Tremaine-Gunn limit is extremely
useful in constraining particle DM models. In certain models, however, the DM
particle mass varies appreciably over time. In this work, we generalize the
phase-space limits on possible DM particle masses to these scenarios. We then
examine the ensuing cosmological implications on the effective DM equation of
state and indirect DM detection.
- Discernible NSI Effects in Long-Baseline Neutrino Experiments
2302.09592 [abs] [pdf]
[abstract]
by Barnali Brahma and Anjan Giri.
Neutrino oscillation in the matter could get affected by the sub-dominant,
yet unknown, non-standard interactions. The upcoming long-baseline (LBL)
neutrino experiments will be sensitive to these effects and can provide
information on the unknown oscillation parameter values. In this article, we
study the parameter degeneracies that can occur in DUNE, T2HK experiments, and
a combination of both due to nonstandard interactions (NSI), arising
simultaneously, from two different off-diagonal sectors, i.e., $e-\mu$ and
$e-\tau$. We derive constraints on both the NSI sectors using the combined
datasets of NO$\nu$A and T2K. Our analysis reveals a significant impact that
dual NSIs may have on the sensitivity of atmospheric mixing angle $\theta_{23}$
in the normal ordering (NO) case. Furthermore, when non-standard interaction
from the $e-\mu$ and $e-\tau$ sectors are included, we see significant changes
in the probabilities for DUNE, T2HK, and as well as a combined analysis
involving both. Moreover, the CP sensitivity gets affected significantly due to
the presence of dual NSIs, and, in addition, the CP asymmetry also exhibits an
appreciable difference.
- Here Comes the Sun: Solar Parameters in Long-Baseline Accelerator
Neutrino Oscillations
2302.08513 [abs] [pdf]
[abstract]
by Peter B. Denton and Julia Gehrlein.
Long-baseline (LBL) accelerator neutrino oscillation experiments, such as
NOvA and T2K in the current generation, and DUNE-LBL and HK-LBL in the coming
years, will measure the remaining unknown oscillation parameters with excellent
precision. These analyses assume external input on the so-called ``solar
parameters,'' $\theta_{12}$ and $\Delta m^2_{21}$, from solar experiments such
as SNO, SK, and Borexino, as well as reactor experiments like KamLAND. Here we
investigate their role in long-baseline experiments. We show that, without
external input on $\Delta m^2_{21}$ and $\theta_{12}$, the sensitivity to
detecting and quantifying CP violation is significantly, but not entirely,
reduced. Thus long-baseline accelerator experiments can actually determine
$\Delta m^2_{21}$ and $\theta_{12}$, and thus all six oscillation parameters,
without input from \emph{any} other oscillation experiment. In particular,
$\Delta m^2_{21}$ can be determined; thus DUNE-LBL and HK-LBL can measure both
the solar and atmospheric mass splittings in their long-baseline analyses
alone. While their sensitivities are not competitive with existing constraints,
they are very orthogonal probes of solar parameters and provide a key
consistency check of a less probed sector of the three-flavor oscillation
picture. Furthermore, we also show that the true values of $\Delta m^2_{21}$
and $\theta_{12}$ play an important role in the sensitivity of other
oscillation parameters such as the CP violating phase $\delta$.
- Probing Cosmic Neutrino Background Charge via Unconventional
Interferometer
2302.08246 [abs] [pdf]
[abstract]
by Chrisna Setyo Nugroho.
If neutrinos carry non-zero electric charge, they would interact directly
with photons. This would induce a phase shift along the photon path in the
optical experiment. We propose a novel idea to detect this phase shift induced
by cosmic neutrino background (CNB) and the photon interaction using laser
interferometry experiment. We show that our setup can probe the CNB neutrino
charge in the order of $10^{-18} \,e- 10^{-17}\, e$. This is quite competitive
with the existing upper bound on neutrino charge from both laboratory
experiments and astrophysical observations.
- Improved sensitivities of ESS$ν$SB from a two-detector fit
2302.07154 [abs] [pdf]
[abstract]
by F. Capozzi, C. Giunti, and C. A. Ternes.
We discuss the improvement of the sensitivity of ESS$\nu$SB to the discovery
of CP violation and to new neutrino physics which can be obtained with a
two-detector fit of the data of the near and far detectors. In particular, we
consider neutrino non-standard interactions generated by very heavy vector
mediators, nonunitary neutrino mixing, and neutrino oscillations due to the
mixing of the ordinary active neutrinos with a light sterile neutrino.
- Signals of a New Gauge Boson from IceCube and Muon $g-2$
2302.03571 [abs] [pdf]
[abstract]
by Dan Hooper, Joaquim Iguaz Juan, and Pasquale D. Serpico.
A $Z'$ boson associated with a broken $U(1)_{L_{\mu} - L_{\tau}}$ gauge
symmetry offers an economical solution to the long-standing $g_\mu-2$ anomaly,
confirmed and strengthened by recent measurements at Fermilab. Here, we revisit
the impact of such a $Z'$ on the spectrum of high-energy astrophysical
neutrinos, as measured by the IceCube experiment. This spectrum has been
observed to exhibit a dip-like feature at $E_{\nu} \sim 0.2-1 \, {\rm PeV}$,
which could plausibly arise from the physics of the sources themselves, but
could also be the consequence of high-energy neutrinos resonantly scattering
with the cosmic neutrino background, mediated by a $Z'$ with a mass on the
order of $m_{Z'} \sim 10 \, {\rm MeV}$. In this study, we calculate the impact
of such a $Z'$ on the high-energy neutrino spectrum for a variety of model
parameters and source distributions. For couplings that can resolve the
$g_{\mu}-2$ anomaly, we find that this model could self-consistently produce a
spectral feature that is consistent with IceCube's measurement, in particular
if the neutrinos observed by IceCube predominantly originate from high-redshift
sources.
- Probing invisible neutrino decay with KM3NeT-ORCA
2302.02717 [abs] [pdf]
[abstract]
by KM3NeT Collaboration, [and 254 more]S. Aiello, A. Albert, S. Alves Garre, Z. Aly, A. Ambrosone, F. Ameli, M. Andre, M. Anghinolfi, M. Anguita, M. Ardid, S. Ardid, J. Aublin, C. Bagatelas, L. Bailly-Salins, B. Baret, S. Basegmez du Pree, Y. Becherini, M. Bendahman, F. Benfenati, E. Berbee, V. Bertin, S. Biagi, M. Boettcher, M. Bou Cabo, J. Boumaaza, M. Bouta, M. Bouwhuis, C. Bozza, H. Brânzaş, R. Bruijn, J. Brunner, R. Bruno, E. Buis, R. Buompane, J. Busto, B. Caiffi, D. Calvo, S. Campion, A. Capone, F. Carenini, V. Carretero, P. Castaldi, S. Celli, L. Cerisy, M. Chabab, N. Chau, A. Chen, R. Cherkaoui El Moursli, S. Cherubini, V. Chiarella, T. Chiarusi, M. Circella, R. Cocimano, J. A. B. Coelho, A. Coleiro, R. Coniglione, P. Coyle, A. Creusot, A. Cruz, G. Cuttone, R. Dallier, Y. Darras, A. De Benedittis, B. De Martino, V. Decoene, R. Del Burgo, I. Di Palma, A. F. Díaz, D. Diego-Tortosa, C. Distefano, A. Domi, C. Donzaud, D. Dornic, M. Dörr, E. Drakopoulou, D. Drouhin, T. Eberl, A. Eddyamoui, T. van Eeden, M. Eff, D. van Eijk, I. El Bojaddaini, S. El Hedri, A. Enzenhöfer, V. Espinosa, G. Ferrara, M. D. Filipović, F. Filippini, L. A. Fusco, J. Gabriel, T. Gal, J. García Méndez, A. Garcia Soto, F. Garufi, C. Gatius Oliver, N. Geißelbrecht, L. Gialanella, E. Giorgio, A. Girardi, I. Goos, S. R. Gozzini, R. Gracia, K. Graf, D. Guderian, C. Guidi, B. Guillon, M. Gutiérrez, L. Haegel, H. van Haren, A. Heijboer, A. Hekalo, L. Hennig, J. J. Hernández-Rey, F. Huang, W. Idrissi Ibnsalih, G. Illuminati, C. W. James, D. Janezashvili, M. de Jong, P. de Jong, B. J. Jung, P. Kalaczyński, O. Kalekin, U. F. Katz, N. R. Khan Chowdhury, G. Kistauri, F. van der Knaap, P. Kooijman, A. Kouchner, V. Kulikovskiy, M. Labalme, R. Lahmann, A. Lakhal, M. Lamoureux, G. Larosa, C. Lastoria, A. Lazo, R. Le Breton, S. Le Stum, G. Lehaut, E. Leonora, N. Lessing, G. Levi, S. Liang, M. Lindsey Clark, F. Longhitano, L. Maderer, J. Majumdar, J. Mańczak, A. Margiotta, A. Marinelli, C. Markou, L. Martin, J. A. Martìnez-Mora, A. Martini, F. Marzaioli, M. Mastrodicasa, S. Mastroianni, K. W. Melis, S. Miccichè, G. Miele, P. Migliozzi, E. Migneco, P. Mijakowski, C. M. Mollo, L. Morales-Gallegos, C. Morley-Wong, A. Moussa, R. Muller, M. R. Musone, M. Musumeci, L. Nauta, S. Navas, C. A. Nicolau, B. Nkosi, B. Ó Fearraigh, A. Orlando, E. Oukacha, J. Palacios González, G. Papalashvili, R. Papaleo, E. J. Pastor Gomez, A. M. Păun, G. E. Păvălaş, C. Pellegrino, S. Peña Martínez, M. Perrin-Terrin, J. Perronnel, V. Pestel, P. Piattelli, O. Pisanti, C. Poirè, V. Popa, T. Pradier, S. Pulvirenti, G. Quéméner, U. Rahaman, N. Randazzo, S. Razzaque, I. C. Rea, D. Real, S. Reck, G. Riccobene, J. Robinson, A. Romanov, F. Salesa Greus, D. F. E. Samtleben, A. Sánchez Losa, M. Sanguineti, C. Santonastaso, D. Santonocito, P. Sapienza, A. Sathe, J. Schnabel, M. F. Schneider, J. Schumann, H. M. Schutte, J. Seneca, I. Sgura, R. Shanidze, A. Sharma, A. Simonelli, A. Sinopoulou, M. V. Smirnov, B. Spisso, M. Spurio, D. Stavropoulos, S. M. Stellacci, M. Taiuti, K. Tavzarashvili, Y. Tayalati, H. Tedjditi, T. Thakore, H. Thiersen, S. Tsagkli, V. Tsourapis, E. Tzamariudaki, V. Van Elewyck, G. Vannoye, G. Vasileiadis, F. Versari, S. Viola, D. Vivolo, H. Warnhofer, J. Wilms, E. de Wolf, H. Yepes-Ramirez, T. Yousfi, S. Zavatarelli, A. Zegarelli, D. Zito, J. D. Zornoza, J. Zúñiga, and N. Zywucka [hide authors].
In the era of precision measurements of the neutrino oscillation parameters,
upcoming neutrino experiments will also be sensitive to physics beyond the
Standard Model. KM3NeT/ORCA is a neutrino detector optimised for measuring
atmospheric neutrinos from a few GeV to around 100 GeV. In this paper, the
sensitivity of the KM3NeT/ORCA detector to neutrino decay has been explored. A
three-flavour neutrino oscillation scenario, where the third neutrino mass
state $\nu_3$ decays into an invisible state, e.g. a sterile neutrino, is
considered. We find that KM3NeT/ORCA would be sensitive to invisible neutrino
decays with $1/\alpha_3=\tau_3/m_3 < 180$~$\mathrm{ps/eV}$ at $90\%$ confidence
level, assuming true normal ordering. Finally, the impact of neutrino decay on
the precision of KM3NeT/ORCA measurements for $\theta_{23}$, $\Delta m^2_{31}$
and mass ordering have been studied. No significant effect of neutrino decay on
the sensitivity to these measurements has been found.
January 2023
- Reconstructing the arrival direction of neutrinos in deep in-ice radio
detectors
2302.00054 [abs] [pdf]
[abstract]
by Ilse Plaisier, Sjoerd Bouma, and Anna Nelles.
In-ice radio detectors are a promising tool for the discovery of EeV
neutrinos. For astrophysics, the implications of such a discovery will rely on
the reconstruction of the neutrino arrival direction. This paper describes a
first complete neutrino arrival direction reconstruction for detectors
employing deep antennas such as RNO-G or planning to employ them like
IceCube-Gen2. We will didactically introduce the challenges of neutrino
direction reconstruction using radio emission in ice, elaborate on the detail
of the algorithm used, and describe the obtainable performance based on a
simulation study and discuss its implication for astrophysics.
- Time Dependent CP-even and CP-odd Signatures of Scalar Ultra-light Dark
Matter in Neutrino Oscillations
2302.00005 [abs] [pdf]
[abstract]
by Marta Losada, [and 4 more]Yosef Nir, Gilad Perez, Inbar Savoray, and Yogev Shpilman [hide authors].
Scalar ultra-light dark matter (ULDM) interacting with neutrinos can induce,
under certain conditions, time-dependent modifications to neutrino oscillation
probabilities. The limit in which the ULDM perturbation can be treated as
constant throughout the neutrino propagation time has been addressed by several
previous works. We complement these by systematically analyzing the opposite
limit -- accounting for the temporal-variations of the ULDM potential by
solving time-dependent Schr\"odinger equations. In particular, we study a novel
two-generations-like CP violating (CPV) signature unique to rapidly oscillating
ULDM. We derive the leading order, time-dependent, corrections to the
oscillation probabilities, both for CP conserving (CPC) and CPV couplings, and
explain how they can be measured in current and future experiments.
- Extraction of neutron density distributions from high-statistics
coherent elastic neutrino-nucleus scattering data
2301.13249 [abs] [pdf]
[abstract]
by D. Aristizabal Sierra.
Forthcoming fixed-target coherent elastic neutrino-nucleus scattering
experiments aim at measurements with $\cal{O}(\text{tonne})$-scale detectors
and substantially reduced systematic and statistical uncertainties. With such
high quality data, the extraction of point-neutron distributions mean-square
radii requires a better understanding of possible theoretical uncertainties. We
quantify the impact of single-nucleon electromagnetic mean-square radii on the
weak-charge form factor and compare results from weak-charge form factor
parametrizations and weak-charge form factor decompositions in terms of elastic
vector proton and neutron form factors, including nucleon form factors
$Q$-dependent terms up to order $Q^2$. We assess as well the differences
arising from results derived using weak-charge form factor decompositions in
terms of elastic vector proton and neutron form factors and a model-independent
approach based solely on the assumption of spherically symmetric nuclear ground
state. We demonstrate the impact of the main effects by assuming pseudo-data
from a one-tonne LAr detector and find that, among the effects and under the
assumptions considered in this paper, weak-charge form factor parametrizations
and weak-charge form factor decompositions in terms of elastic vector proton
and neutron form factors enable the extraction of the $^{40}\text{Ar}$
point-neutron distribution mean-square radius with a $\sim 15\%$ accuracy. With
a substantial reduction of the beam-related neutron and steady-state
backgrounds a $\sim 1\%$ precision extraction seems feasible, using either of
the two approaches.
- Theoretical Aspect of Nonunitarity in Neutrino Oscillation
2301.12960 [abs] [pdf]
[abstract]
by Chee Sheng Fong.
Nonunitarity can arise in neutrino oscillation when the matrix with elements
$\mathbf{U}_{\alpha i}$ which relate the neutrino flavor $\alpha$ and mass $i$
eigenstates is not unitary when sum over the kinematically accessible mass
eigenstates or over the three Standard Model flavors. We review how high scale
nonunitarity arises after integrating out new physics which is not accessible
in neutrino oscillation experiments. In particular, we stress that high scale
unitarity violation is only apparent and what happens is that the neutrino
flavor states become nonorthogonal due to new physics. Since the flavor space
is complete, unitarity has to be preserved in time evolution and that the
probabilities of a flavor state oscillates to all possible flavor states always
sum up to unity. We highlight the need to modify the expression of probability
to preserve unitarity when the flavor states are nonorthogonal. We will
continue to call this high scale unitarity violation in reference to a
nonunitary $\mathbf{U}$. We contrast this to the low scale nonunitarity
scenario in which there are new states accessible in neutrino oscillation
experiments but the oscillations involving these states are fast enough such
that they are averaged out. We further derive analytical formula for the
neutrino oscillation amplitude involving $N$ neutrino flavors without assuming
a unitarity $\mathbf{U}$ which allows us to prove a theorem that if
$\left(\mathbf{U}\mathbf{U}^{\dagger}\right)_{\alpha\beta}=0$ for all
$\alpha\neq\beta$, then the neutrino oscillation probability in an arbitrary
matter potential is indistinguishable from the unitarity scenario.
Independently of matter potential, while nonunitarity effects for high scale
nonunitarity scenario disappear as
$\left(\mathbf{U}\mathbf{U}^{\dagger}\right)_{\alpha\beta}\to 0$ for all
$\alpha\neq\beta$, low scale nonunitarity effects can remain.
- Klein-Gordon Equation with Self-Interaction $λφ^4$ and
Arbitrary Spherical Source Terms
2301.11106 [abs] [pdf]
[abstract]
by Peter B. Denton.
The Klein-Gordon equation for a scalar field sourced by a spherically
symmetric background is an interesting second-order differential equation with
applications in particle physics, astrophysics, and elsewhere. Here we present
solutions for generic source density profiles in the case where the scalar
field has no interactions or a mass term. For a $\lambda\phi^4$
self-interaction term, we provide the necessary expressions for a numerical
computation, an algorithm to numerically match the initial conditions from
infinity to the origin, and an accurate guess of that initial condition. We
also provide code to perform the numerical calculations that can be adapted for
arbitrary density profiles.
- Neutrino Electromagnetic Properties and the Weak Mixing Angle at the LHC
Forward Physics Facility
2301.10254 [abs] [pdf]
[abstract]
by Roshan Mammen Abraham, [and 3 more]Saeid Foroughi-Abari, Felix Kling, and Yu-Dai Tsai [hide authors].
The LHC produces an intense beam of highly energetic neutrinos of all three
flavors in the forward direction, and the Forward Physics Facility (FPF) has
been proposed to house a suite of experiments taking advantage of this
opportunity. In this study, we investigate the FPF's potential to probe the
neutrino electromagnetic properties, including neutrino millicharge, magnetic
moment, and charge radius. We find that, due to the large flux of tau neutrinos
at the LHC, the FPF detectors will be able to provide the strongest
laboratory-based sensitivity to the tau neutrino magnetic moment and
millicharge by searching for excess in low recoil energy electron scattering
events. We also find that, by precisely measuring the rate of neutral current
deep inelastic scattering events, the FPF detectors have the potential to
obtain the strongest experimental bounds on the neutrino charge radius for the
electron neutrino, and one of the leading bounds for the muon neutrino flavor.
The same signature could also be used to measure the weak mixing angle, and we
estimate that $\sin^2 \theta_W$ could be measured to about $3\%$ precision at a
scale $Q \sim 10$ GeV, shedding new light on the long-standing NuTeV anomaly.
- Sterile Neutrino Shape-shifting Caused by Dark Matter
2301.09651 [abs] [pdf]
[abstract]
by Hooman Davoudiasl and Peter B. Denton.
Light sterile neutrinos with a mass of $\sim 1$ eV continue to be interesting
due to multiple hints from terrestrial experiments. This simple hypothesis
suffers from strong astrophysical constraints, in particular from the early
universe as well as solar neutrinos. We develop a cosmologically viable
proposal consistent with the terrestrial hints, as well as solar constraints,
by sourcing the sterile neutrino's mass from ordinary matter via an ultralight
scalar $\phi$ which can also be the dark matter. In this scenario, the
experimentally implied $\sim 1$ eV sterile neutrino mass is a local value and
changes throughout spacetime.
- Synergy Between Hubble Tension Motivated Self-Interacting Neutrino and
KeV-Sterile Neutrino Dark Matter
2301.09552 [abs] [pdf]
[abstract]
by Mansi Dhuria and Abinas Pradhan.
The discrepancy between the value of Hubble constant measured by CMB
observations and local low-redshift based observations has proposed many
solutions which require the existence of Physics beyond Standard Model (SM).
One of the interesting solutions is based on considering the strong
self-interaction between Standard Model (SM) neutrinos through an additional
scalar/vector mediator. Interestingly, the strong self-interaction between SM
neutrinos also play an important role in obtaining KeV-sterile neutrino as a
viable Dark Matter (DM) candidate through the famous Dodelson-Widrow mechanism.
In this work, we have tried to find the synergy between the parameter space of
active-sterile neutrino mixing vs mass of sterile neutrino allowed by Hubble
tension solution and the requirement of getting KeV-sterile neutrino as DM
candidate. Interestingly, we get a large amount of parameter space that is
consistent with both the requirements and also free from X-Ray constraints.
Finally, we have embedded this scenario in a consistent supersymmetric model of
particle physics. In this framework, we have shown that the value of sterile
neutrino mass, SM neutrino mass and the required mixing angle can be naturally
obtained by considering the supersymmetry breaking scale to be around O(10)
TeV. Thus, it would give an interesting testing ground for supersymmetry as
well as signatures of Warm Dark Matter (WDM).
- NGC 1068 constraints on neutrino-dark matter scattering
2301.08756 [abs] [pdf]
[abstract]
by James M. Cline and Matteo Puel.
The IceCube collaboration has observed the first steady-state point source of
high-energy neutrinos, coming from the active galaxy NGC 1068. If neutrinos
interacted strongly enough with dark matter, the emitted neutrinos would have
been impeded by the dense spike of dark matter surrounding the supermassive
black hole at the galactic center, which powers the emission. We derive a
stringent upper limit on the scattering cross section between neutrinos and
dark matter based on the observed events and theoretical models of the dark
matter spike. The bound can be stronger than that obtained by the single
IceCube neutrino event from the blazar TXS 0506+056 for some spike models.
- Can Neutrino Self-interactions Save Sterile Neutrino Dark Matter?
2301.08299 [abs] [pdf]
[abstract]
by Rui An, [and 3 more]Vera Gluscevic, Ethan O. Nadler, and Yue Zhang [hide authors].
Sterile neutrinos only interact with the Standard Model through the neutrino
sector, and thus represent a simple dark matter (DM) candidate with many
potential astrophysical and cosmological signatures. Recently, sterile
neutrinos produced through self-interactions of active neutrinos have received
attention as a particle candidate that can yield the entire observed DM relic
abundance without violating the most stringent constraints from X-ray
observations. We examine consistency of this production mechanism with the
abundance of small-scale structure in the universe, as captured by the
population of ultra-faint dwarf galaxies orbiting the Milky Way, and derive a
lower bound on the sterile-neutrino particle mass of $37.2$ keV. Combining
these results with previous limits from particle physics and astrophysics
excludes $100\%$ sterile neutrino DM produced by strong neutrino self-coupling,
mediated by a heavy ($\gtrsim 1~\mathrm{GeV}$) scalar particle; however, data
permits sterile-neutrino DM production via a light mediator.
- Mineral Detection of Neutrinos and Dark Matter. A Whitepaper
2301.07118 [abs] [pdf]
[abstract]
by Sebastian Baum, [and 68 more]Patrick Stengel, Natsue Abe, Javier F. Acevedo, Gabriela R. Araujo, Yoshihiro Asahara, Frank Avignone, Levente Balogh, Laura Baudis, Yilda Boukhtouchen, Joseph Bramante, Pieter Alexander Breur, Lorenzo Caccianiga, Francesco Capozzi, Juan I. Collar, Reza Ebadi, Thomas Edwards, Klaus Eitel, Alexey Elykov, Rodney C. Ewing, Katherine Freese, Audrey Fung, Claudio Galelli, Ulrich A. Glasmacher, Arianna Gleason, Noriko Hasebe, Shigenobu Hirose, Shunsaku Horiuchi, Yasushi Hoshino, Patrick Huber, Yuki Ido, Yohei Igami, Norito Ishikawa, Yoshitaka Itow, Takashi Kamiyama, Takenori Kato, Bradley J. Kavanagh, Yoji Kawamura, Shingo Kazama, Christopher J. Kenney, Ben Kilminster, Yui Kouketsu, Yukiko Kozaka, Noah A. Kurinsky, Matthew Leybourne, Thalles Lucas, William F. McDonough, Mason C. Marshall, Jose Maria Mateos, Anubhav Mathur, Katsuyoshi Michibayashi, Sharlotte Mkhonto, Kohta Murase, Tatsuhiro Naka, Kenji Oguni, Surjeet Rajendran, Hitoshi Sakane, Paola Sala, Kate Scholberg, Ingrida Semenec, Takuya Shiraishi, Joshua Spitz, Kai Sun, Katsuhiko Suzuki, Erwin H. Tanin, Aaron Vincent, Nikita Vladimirov, Ronald L. Walsworth, and Hiroko Watanabe [hide authors].
Minerals are solid state nuclear track detectors - nuclear recoils in a
mineral leave latent damage to the crystal structure. Depending on the mineral
and its temperature, the damage features are retained in the material from
minutes (in low-melting point materials such as salts at a few hundred degrees
C) to timescales much larger than the 4.5 Gyr-age of the Solar System (in
refractory materials at room temperature). The damage features from the $O(50)$
MeV fission fragments left by spontaneous fission of $^{238}$U and other heavy
unstable isotopes have long been used for fission track dating of geological
samples. Laboratory studies have demonstrated the readout of defects caused by
nuclear recoils with energies as small as $O(1)$ keV. This whitepaper discusses
a wide range of possible applications of minerals as detectors for $E_R \gtrsim
O(1)$ keV nuclear recoils: Using natural minerals, one could use the damage
features accumulated over $O(10)$ Myr$-O(1)$ Gyr to measure astrophysical
neutrino fluxes (from the Sun, supernovae, or cosmic rays interacting with the
atmosphere) as well as search for Dark Matter. Using signals accumulated over
months to few-years timescales in laboratory-manufactured minerals, one could
measure reactor neutrinos or use them as Dark Matter detectors, potentially
with directional sensitivity. Research groups in Europe, Asia, and America have
started developing microscopy techniques to read out the $O(1) - O(100)$ nm
damage features in crystals left by $O(0.1) - O(100)$ keV nuclear recoils. We
report on the status and plans of these programs. The research program towards
the realization of such detectors is highly interdisciplinary, combining
geoscience, material science, applied and fundamental physics with techniques
from quantum information and Artificial Intelligence.
- Multifield Ultralight Dark Matter
2301.07114 [abs] [pdf]
[abstract]
by Mateja Gosenca, [and 6 more]Andrew Eberhardt, Yourong Wang, Benedikt Eggemeier, Emily Kendall, J. Luna Zagorac, and Richard Easther [hide authors].
Ultralight dark matter (ULDM) is usually taken to be a single scalar field.
Here we explore the possibility that ULDM consists of $N$ light scalar fields
with only gravitational interactions. This configuration is more consistent
with the underlying particle physics motivations for these scenarios than a
single ultralight field. ULDM halos have a characteristic granular structure
that increases stellar velocity dispersion and can be used as observational
constraints on ULDM models. In multifield simulations, we find that inside a
halo the amplitude of the total density fluctuations decreases as $1/\sqrt{N}$
and that the fields do not become significantly correlated over cosmological
timescales. Smoother halos heat stellar orbits less efficiently, reducing the
velocity dispersion relative to the single field case and thus weakening the
observational constraints on the field mass. Analytically, we show that for $N$
equal-mass fields with mass $m$ the ULDM contribution to the stellar velocity
dispersion scales as $1/(N m^3)$. Lighter fields heat the most efficiently and
if the smallest mass $m_L$ is significantly below the other field masses the
dispersion scales as $1/(N^2 m_L^3)$.
- EFT analysis of New Physics at COHERENT
2301.07036 [abs] [pdf]
[abstract]
by Víctor Bresó-Pla, [and 3 more]Adam Falkowski, Martín González-Alonso, and Kevin Monsálvez-Pozo [hide authors].
Using an effective field theory approach, we study coherent neutrino
scattering on nuclei, in the setup pertinent to the COHERENT experiment. We
include non-standard effects both in neutrino production and detection, with an
arbitrary flavor structure, with all leading Wilson coefficients simultaneously
present, and without assuming factorization in flux times cross section. A
concise description of the COHERENT event rate is obtained by introducing three
generalized weak charges, which can be associated (in a certain sense) to the
production and scattering of $\nu_e$, $\nu_\mu$ and $\bar{\nu}_\mu$ on the
nuclear target. Our results are presented in a convenient form that can be
trivially applied to specific New Physics scenarios. In particular, we find
that existing COHERENT measurements provide percent level constraints on two
combinations of Wilson coefficients. These constraints have a visible impact on
the global SMEFT fit, even in the constrained flavor-blind setup. The
improvement, which affects certain 4-fermion LLQQ operators, is significantly
more important in a flavor-general SMEFT. Our work shows that COHERENT data
should be included in electroweak precision studies from now on.
- Report of the 2021 U.S. Community Study on the Future of Particle
Physics (Snowmass 2021) Summary Chapter
2301.06581 [abs] [pdf]
[abstract]
by Joel N. Butler, [and 42 more]R. Sekhar Chivukula, André de Gouvêa, Tao Han, Young-Kee Kim, Priscilla Cushman, Glennys R. Farrar, Yury G. Kolomensky, Sergei Nagaitsev, Nicolás Yunes, Stephen Gourlay, Tor Raubenheimer, Vladimir Shiltsev, Kétévi A. Assamagan, Breese Quinn, V. Daniel Elvira, Steven Gottlieb, Benjamin Nachman, Aaron S. Chou, Marcelle Soares-Santos, Tim M. P. Tait, Meenakshi Narain, Laura Reina, Alessandro Tricoli, Phillip S. Barbeau, Petra Merkel, Jinlong Zhang, Patrick Huber, Kate Scholberg, Elizabeth Worcester, Marina Artuso, Robert H. Bernstein, Alexey A. Petrov, Nathaniel Craig, Csaba Csáki, Aida X. El-Khadra, Laura Baudis, Jeter Hall, Kevin T. Lesko, John L. Orrell, Julia Gonski, Fernanda Psihas, and Sara M. Simon [hide authors].
The 2021-22 High-Energy Physics Community Planning Exercise (a.k.a.
``Snowmass 2021'') was organized by the Division of Particles and Fields of the
American Physical Society. Snowmass 2021 was a scientific study that provided
an opportunity for the entire U.S. particle physics community, along with its
international partners, to identify the most important scientific questions in
High Energy Physics for the following decade, with an eye to the decade after
that, and the experiments, facilities, infrastructure, and R&D needed to pursue
them. This Snowmass summary report synthesizes the lessons learned and the main
conclusions of the Community Planning Exercise as a whole and presents a
community-informed synopsis of U.S. particle physics at the beginning of 2023.
This document, along with the Snowmass reports from the various subfields, will
provide input to the 2023 Particle Physics Project Prioritization Panel (P5)
subpanel of the U.S. High-Energy Physics Advisory Panel (HEPAP), and will help
to guide and inform the activity of the U.S. particle physics community during
the next decade and beyond.
- Distortion of neutrino oscillations by dark photon dark matter
2301.04152 [abs] [pdf]
[abstract]
by Gonzalo Alonso-Álvarez, Katarina Bleau, and James M. Cline.
A weakly coupled and light dark photon coupling to lepton charges
$L_\mu-L_\tau$ is an intriguing dark matter candidate whose coherent
oscillations alter the dispersion relations of leptons. We study how this
effect modifies the dynamics of neutrino flavor conversions, focusing on long
baseline and solar oscillations. We analyze data from the T2K, SNO, and
Super-Kamiokande experiments in order to obtain world-leading limits on the
dark photon gauge coupling for masses below $\sim 10^{-11}\,\mathrm{eV}$.
Degeneracies between shifts in the neutrino mass-squared differences and mixing
angles and the new physics effect significantly relax the current constrains on
the neutrino vacuum oscillation parameters.
- Neutrino Physics and Astrophysics Overview
2301.02935 [abs] [pdf]
[abstract]
by Floyd W. Stecker.
This book chapter presents an overview of the historical experimental and
theoretical developments in neutrino physics and astrophysics and also the
physical properties of neutrinos, as well as the physical processes involving
neutrinos. It also discusses the role of neutrinos in astrophysics and
cosmology. Correction to tex file made.
- Constraints from the duration of supernova neutrino burst on on-shell
light gauge boson production by neutrinos
2301.00661 [abs] [pdf]
[abstract]
by David G. Cerdeño, Marina Cermeño, and Yasaman Farzan.
In this article, we study the on-shell production of low-mass vector
mediators from neutrino-antineutrino coalescence in the core of proto-neutron
stars. Taking into account the radial dependence of the density, energy, and
temperature inside the proto-neutron star, we compute the neutrino-antineutrino
interaction rate in the star interior in the well-motivated
$U(1)_{L_{\mu}-L_{\tau}}$ model. First, we determine the values of the coupling
above which neutrino-antineutrino interactions dominate over the Standard Model
neutrino-nucleon scattering. We argue that, although in this regime a
redistribution of the neutrino energies might take place, making low-energy
neutrinos more trapped, this only affects a small part of the neutrino
population and it cannot be constrained with the SN 1987A data. Thus, contrary
to previous claims, the region of the parameter space where the
$U(1)_{L_{\mu}-L_{\tau}}$ model explains the discrepancy in the muon anomalous
magnetic moment is not ruled out. We then focus on small gauge couplings, where
the decay length of the new gauge boson is larger than the neutrino-nucleon
mean free path, but still smaller than the size of proto-neutron star. We show
that in this regime, the on-shell production of a long-lived $Z'$ and its
subsequent decay into neutrinos can significantly reduce the duration of the
neutrino burst, probing values of the coupling below ${\cal O}(10^{-7})$ for
mediator masses between 10 and 100 MeV. This disfavours new areas of the
parameter space of the $U(1)_{L_{\mu}-L_{\tau}}$ model.
- Impact of CP violation searches at MOMENT experiment with sterile
neutrinos
2301.00390 [abs] [pdf]
[abstract]
by Kiran Sharma and Sudhanwa Patra.
We examine the scope of the MOMENT experiment in the context of CP violation
searches with the presence of extra eV scale sterile neutrino. MOMENT is a
proposed short baseline neutrino oscillation experiment using muon beams for
neutrinos production, making it advantageous over $\pi_0$ background and other
technical difficulties. We work over the first oscillation maxima which matches
the peak value of flux with a run time of 5 years for both neutrino and
anti-neutrino modes. We perform the bi-probability studies for both 3 and 3+1
flavor mixing schemes. The CP violation sensitivities arising from the
fundamental CP phase $\delta_{13}$ and unknown CP phase $\delta_{14}$ are
explored at the firm footing. The slight deteriorates are observed in CP
violations induced by $\delta_{13}$ as the presence of sterile neutrino is
considered. We also look at the reconstruction of CP violations phases
$\delta_{13}$ and $\delta_{14}$ and the MOMENT experiment shows significant
capabilities in the precise measurement of $\delta_{13}$ phase.
December 2022
- Bump-hunting in the diffuse flux of high-energy cosmic neutrinos
2301.00024 [abs] [pdf]
[abstract]
by Damiano F. G. Fiorillo and Mauricio Bustamante.
The origin of the bulk of the high-energy astrophysical neutrinos seen by
IceCube, with TeV--PeV energies, is unknown. If they are made in photohadronic,
i.e., proton-photon, interactions in astrophysical sources, this may manifest
as a bump-like feature in their diffuse flux, centered around a characteristic
energy. We search for evidence of this feature, allowing for variety in its
shape and size, in 7.5 years of High-Energy Starting Events (HESE) collected by
the IceCube neutrino telescope, and make forecasts using larger data samples
from upcoming neutrino telescopes. Present-day data reveals no evidence of
bump-like features, which allows us to constrain candidate populations of
photohadronic neutrino sources. Near-future forecasts show promising potential
for stringent constraints or decisive discovery of bump-like features. Our
results provide new insight into the origins of high-energy astrophysical
neutrinos, complementing those from point-source searches.
- Neutron capture-induced nuclear recoils as background for
CE$ν$NS~measurements at reactors
2212.14148 [abs] [pdf]
[abstract]
by A. J. Biffl, [and 3 more]A. Gevorgian, K. Harris, and A. N. Villano [hide authors].
Nuclear reactors represent a promising neutrino source for CE$\nu$NS
(coherent-elastic neutrino-nucleus scattering) searches. However, reactor sites
also come with high ambient neutron flux. Neutron capture-induced nuclear
recoils can create a spectrum that strongly overlaps the CE$\nu$NS signal for
recoils $\lesssim$\,100\,eV for nuclear reactor measurements in silicon or
germanium detectors. This background can be particularly critical for low-power
research reactors providing a moderate neutrino flux. In this work we quantify
the impact of this background and show that, for a measurement 10\,m from a
1\,MW reactor, the effective thermal neutron flux should be kept below
$\sim$~7$\times$~10$^{-4}$\,n/cm$^2$s so that the CE$\nu$NS events can be
measured at least at a 5$\sigma$ level with germanium detectors in 100~kg\,yr
exposure time. This flux corresponds to 60\% of the sea-level flux but needs to
be achieved in a nominally high-flux (reactor) environment. Improved detector
resolution can help the measurements, but the thermal flux is the key parameter
for the sensitivity of the experiment. For silicon detectors, the constraint is
even stronger and thermal neutron fluxes must be near an order of magnitude
lower. This constraint highlights the need of an effective thermal neutron
mitigation strategy for future low threshold CE$\nu$NS searches. In particular,
the neutron capture-induced background can be efficiently reduced by active
veto systems tagging the deexcitation gamma following the capture.
- Neutrino Oscillations in Matter using the Adjugate of the Hamiltonian
2212.12565 [abs] [pdf]
[abstract]
by Asli Abdullahi and Stephen J. Parke.
We revisit neutrino oscillations in constant matter density for a number of
different scenarios: three flavors with the standard Wolfenstein matter
potential, four flavors with standard matter potential and three flavors with
non-standard matter potentials. To calculate the oscillation probabilities for
these scenarios one must determine the eigenvalues and eigenvectors of the
Hamiltonians. We use a method for calculating the eigenvalues that is well
known, determination of the zeros of determinant of matrix $(\lambda I -H)$,
where H is the Hamiltonian, I the identity matrix and $\lambda$ is a scalar. To
calculate the associated eigenvectors we use a method that is little known in
the particle physics community, the calculation of the adjugate (transpose of
the cofactor matrix) of the same matrix, $(\lambda I -H)$. This method can be
applied to any Hamiltonian, but provides a very simple way to determine the
eigenvectors for neutrino oscillation in matter, independent of the complexity
of the matter potential. This method can be trivially automated using the
Faddeev-LeVerrier algorithm for numerical calculations. For the above scenarios
we derive a number of quantities that are invariant of the matter potential,
many are new such as the generalization of the Naumov-Harrison-Scott identity
for four or more flavors of neutrinos. We also show how these matter potential
independent quantities become matter potential dependent when off-diagonal
non-standard matter effects are included.
- Lepton-flavour-violating tau decays from triality
2212.09760 [abs] [pdf]
[abstract]
by Innes Bigaran, [and 4 more]Xiao-Gang He, Michael A. Schmidt, German Valencia, and Raymond Volkas [hide authors].
Motivated by flavour symmetry models, we construct theories based on a
low-energy limit featuring lepton flavour triality that have the
flavour-violating decays $\tau^\pm \to \mu^\pm \mu^\pm e^\mp$ and $\tau^\pm \to
e^\pm e^\pm \mu^\mp$ as the main phenomenological signatures of physics beyond
the standard model. These decay modes are expected to be probed in the near
future with increased sensitivity by the Belle II experiment at the SuperKEKB
collider. The simple standard model extensions featured have doubly-charged
scalars as the mediators of the above decay processes. The phenomenology of
these extensions is studied here in detail.
- Inspection of the detection cross section dependence of the Gallium
Anomaly
2212.09722 [abs] [pdf]
[abstract]
by C. Giunti, [and 3 more]Y. F. Li, C. A. Ternes, and Z. Xin [hide authors].
We discuss in detail the dependence of the Gallium Anomaly on the detection
cross section. We provide updated values of the size of the Gallium Anomaly and
find that its significance is larger than about $5\sigma$ for all the detection
cross section models. We discuss the dependence of the Gallium Anomaly on the
assumed value of the half life of ${}^{71}\text{Ge}$, which determines the
cross sections of the transitions from the ground state of ${}^{71}\text{Ga}$
to the ground state of ${}^{71}\text{Ge}$. We show that a value of the
${}^{71}\text{Ge}$ half life which is larger than the standard one can reduce
or even solve the Gallium Anomaly. Considering the short-baseline neutrino
oscillation interpretation of the Gallium Anomaly, we show that a value of the
${}^{71}\text{Ge}$ half life which is larger than the standard one can reduce
the tension with the results of other experiments. Since the standard value of
the ${}^{71}\text{Ge}$ half life was measured in 1985, we advocate the
importance of new measurements with modern technique and apparatus for a better
assessment of the Gallium Anomaly.
- Adding Stroboscopic Muon Information For Reduction of Systematic
Uncertainties in DUNE
2212.09524 [abs] [pdf]
[abstract]
by Henry J. Frisch.
Muons have a similar latency/energy correlation from pion decay as do the
neutrinos, and hence in each time-slice in a stroboscopic analysis measurements
of their momentum spectra can reduce systematic uncertainties due to flux.
There are, however, unique issues for muons: 1) during standard neutrino
data-taking muon measurements in the forward direction must be in formidable
high-flux high-radiation environments; 2) because of the very high incident
hadron flux in the Absorber Hall, muons must be detected after a thick
absorber, imposing a range cutoff at a momentum much above the minimum neutrino
momentum of interest; 3) the muon velocity, unlike that of neutrinos, differs
from $c$, and so the muon detected time will require correction for the muon
flight path, requiring measurement of the muon momentum; 4) multiple scattering
is significant for low-momentum muons, and so a `good geometry' is essential
for precision muon flux measurements; and 5) developments in psec timing allow
muon momenta in the momentum region of interest to be measured precisely by
time-of-flight over short distances with photodetectors of a few-psec
resolution. Here we advocate that a program of extensive precise low-intensity
muon momentum spectrum measurements be carried out early in the LBNF program
before the Absorber Hall becomes too hot. The low-momentum muon spectra taken
in this experiment would be cross-normalized to the high-intensity neutrino
data through the currently planned muon monitors which can operate in both the
low and high intensity geometries.
While beyond the scope of uniquely muon-related issues, the note includes a
proposal for an long-base-line oscillation analysis strategy that exploits
stroboscopic information for both neutrinos and muons to reduce systematic
uncertainties on the neutrino fluxes and event selection in Far and Near
detectors.
- Strong Lensing of High-Energy Neutrinos
2212.08793 [abs] [pdf]
[abstract]
by Yoon Chan Taak, [and 3 more]Tommaso Treu, Yoshiyuki Inoue, and Alexander Kusenko [hide authors].
We consider the effects of strong gravitational lensing by galaxy-scale
deflectors on the observations of high-energy (E$\gg$GeV) neutrinos (HEN). For
HEN at cosmological distances, the optical depth for multiple imaging is $\sim
10^{-3}$, implying that while we do not expect any multiply imaged HEN with
present samples, next-generation experiments should be able to detect the first
such event. We then present the distribution of expected time delays to aid in
the identification of such events, in combination with directional and energy
information. In order to assist in the evaluation of HEN production mechanisms,
we illustrate how lensing affects the observed number counts for a variety of
intrinsic luminosity functions of the source population. Finally, we see that
the lensing effects on the cosmic neutrino background flux calculation would be
negligible by taking kpc-scale jets as an example.
- Non-adiabatic Level Crossing in Resonant Neutrino Oscillations
2212.06978 [abs] [pdf]
[abstract]
by Stephen J. Parke.
Analytic results are presented for the probability of detecting an electron
neutrino after passage through a resonant oscillation region. If the electron
neutrino is produced far above the resonance density, this probability is
simply given by $\langle \,P_{\nu_e} \, \rangle \approx \sin^2 \theta_0+
P_\text{x} \cos 2 \theta_0$, where $\theta_0$ is the vacuum mixing angle. The
probability is averaged over the production as well as the detection positions
of the neutrino and $P_\text{x} $ is the Landau-Zener transition probability
between adiabatic states. Finally, this result is applied to resonance
oscillations within the solar interior.
- Invisible Neutrino Decays as Origin of TeV Gamma Rays from GRB221009A
2212.03477 [abs] [pdf]
[abstract]
by Jihong Huang, [and 3 more]Yilin Wang, Bingrong Yu, and Shun Zhou [hide authors].
Recently, the LHAASO collaboration has observed the gamma rays of energies up
to ten TeV from the gamma-ray burst GRB221009A, which has stimulated the
community of astronomy, particle physics and astrophysics to propose various
possible interpretations. In this paper, we put forward a viable scenario that
neutrinos are produced together with TeV photons in the gamma-ray burst and
gradually decay into the axion-like particles, which are then converted into
gamma rays in the galactic magnetic fields. In such a scenario, the tension
between previous axion-like particle interpretations and the existing
observational constraints on the relevant coupling constant and mass can be
relaxed.
- Matter effect in presence of a sterile neutrino and resolution of the
octant degeneracy using a liquid argon detector
2212.02949 [abs] [pdf]
[abstract]
by Animesh Chatterjee, Srubabati Goswami, and Supriya Pan.
Results from the experiments like LSND, and MiniBooNE hint towards the
possible presence of an extra eV scale sterile neutrino. The addition of such a
neutrino will significantly impact the standard three flavour neutrino
oscillations; in particular, it can give rise to additional degeneracies due to
new sterile parameters. In our work, we investigate how the sensitivity to
determine the octant of the neutrino mixing angle $\theta_{23}$ is affected by
introducing a sterile neutrino to the standard neutrino oscillation framework.
We compute the oscillation probabilities in presence of a sterile neutrino,
analytically, using the approximation that $\Delta_{21}$, the smallest mass
squared difference, is zero. We use these probabilities to understand the
degeneracies analytically at different baselines. We present our results of the
sensitivity to octant of $\theta_{23}$ for beam neutrinos using a liquid argon
time projection chamber (LArTPC). We also obtain octant sensitivity using
atmospheric neutrinos using the same LArTPC detector without any charge
identification capability. In addition, we include the charge tagging
capability of muon capture in argon which allows one to differentiate between
muon neutrino and antineutrino events. The combined sensitivity of beam and
atmospheric neutrinos in a similar experimental setup is also delineated. We
observe that by combining simulated data from the beam and atmospheric
neutrinos (including charge-id for muons), the sensitivity to the octant of
$\theta_{23}$ for true values of $\theta_{23}=41^\circ(49^\circ)$ exceeds
$4\sigma(3\sigma)$ for more than $50\%$ values of true $\delta_{13}$.
- Snowmass Neutrino Frontier: NF01 Topical Group Report on Three-Flavor
Neutrino Oscillations
2212.00809 [abs] [pdf]
[abstract]
by Peter B. Denton, [and 7 more]Megan Friend, Mark D. Messier, Hirohisa A. Tanaka, Sebastian Böser, João A. B. Coelho, Mathieu Perrin-Terrin, and Tom Stuttard [hide authors].
This is the report from the Snowmass NF01 topical group and colleagues on the
current status and expected future progress to understand the three-flavor
neutrino oscillation picture.
- Probing Pseudo-Dirac Neutrinos with Astrophysical Sources at IceCube
2212.00737 [abs] [pdf]
[abstract]
by Kiara Carloni, [and 4 more]Ivan Martinez-Soler, Carlos A. Arguelles, K. S. Babu, and P. S. Bhupal Dev [hide authors].
The recent observation of NGC 1068 by the IceCube Neutrino Observatory has
opened a new window to neutrino physics with astrophysical baselines. In this
Letter, we propose a new method to probe the nature of neutrino masses using
these observations. In particular, our method enables searching for signatures
of pseudo-Dirac neutrinos with mass-squared differences that reach down to
$\delta m^2 \gtrsim 10^{-21}~\text{eV}^2$, improving the reach of terrestrial
experiments by more than a billion. Finally, we discuss how the discovery of a
constellation of neutrino sources can further increase the sensitivity and
cover a wider range of $\delta m^2$ values.
November 2022
- The Cosmic Neutrino Background on the Surface of the Earth
2212.00036 [abs] [pdf]
[abstract]
by Asimina Arvanitaki and Savas Dimopoulos.
We argue that the reflection of relic neutrinos from the surface of the Earth
results in a significant local $\nu-\bar{\nu}$ asymmetry, far exceeding the
expected primordial lepton asymmetry. The net fractional electron neutrino
number $\frac{n_{\nu_e}-n_{\bar{\nu}_e}}{n_{\nu_e}}$ is up to
$\mathcal{O}(10^5) \sqrt{\frac{m_\nu}{0.1~\text{eV}}}$ larger than that implied
by the baryon asymmetry. This enhancement is due to the weak 4-Fermi repulsion
of the $\nu_e$ from ordinary matter which slows down the $\nu_e$ near the
Earth's surface, and to the resulting evanescent neutrino wave that penetrates
below the surface. This repulsion thus creates a net $\nu_e$ overdensity in a
shell $\sim 7~\text{meters} \sqrt{\frac{0.1~\text{eV}}{m_\nu}}$ thick around
the Earth's surface. Similarly the repulsion between $\bar{\nu}_\mu$ or
$\bar{\nu}_\tau$ and ordinary matter creates an overdensity of $\bar{\nu}_{\mu,
\tau}$ of similar size. These local enhancements increase the size of
$\mathcal{O}(G_F)$ torques of the $C\nu B$ on spin-polarized matter by a factor
of order $10^5$. In addition, they create a gradient of the net neutrino
density which naturally provides a way out of the forty-year-old ``no-go''
theorems on the vanishing of $\mathcal{O}(G_F)$ forces. The torque resulting
from such a gradient force can be $10^8$ times larger than that of earlier
proposals. Although the size of these effects is still far from current reach,
they may point to new directions for $C\nu B$ detection.
- Multiplicity of TeV muons in air showers detected with IceTop and
IceCube
2211.16970 [abs] [pdf]
[abstract]
by Stef Verpoest.
The IceCube Neutrino Observatory at the South Pole can provide unique tests
of muon production models in extensive air showers by measuring both the
low-energy (GeV) and high-energy (TeV) muon components. We present here a
measurement of the TeV muon content in near-vertical air showers detected with
IceTop in coincidence with IceCube. The primary cosmic-ray energy is estimated
from the dominant electromagnetic component of the air shower observed at the
surface. The high-energy muon content of the shower is studied based on the
energy losses measured in the deep detector. Using a neural network, the
primary energy and the multiplicity of TeV muons are estimated on an
event-by-event basis. The baseline analysis determines the average multiplicity
as a function of the primary energy between 2.5 PeV and 250 PeV using the
hadronic interaction model Sibyll 2.1. Results obtained using simulations based
on the post-LHC models QGSJet-II.04 and EPOS-LHC are presented for primary
energies up to 100 PeV. For all three hadronic interaction models, the
measurements of the TeV muon content are consistent with the predictions
assuming recent composition models. Comparing the results to measurements of
GeV muons in air showers reveals a tension in the obtained composition
interpretation based on the post-LHC models.
- Neutrino Non-standard Interactions with arbitrary couplings to u and d
quarks
2211.15686 [abs] [pdf]
[abstract]
by Nicolás Bernal and Yasaman Farzan.
We introduce a model for Non-Standard neutral current Interaction (NSI)
between neutrinos and the matter fields, with an arbitrary coupling to the up
and down quarks. The model is based on a new $U(1)$ gauge symmetry with a light
gauge boson that mixes with the photon. We show that the couplings to the $u$
and $d$ quarks can have a ratio such that the contribution from NSI to the
Coherent Elastic Neutrino-Nucleus Scattering (CE$\nu$NS) amplitude vanishes,
relaxing the bound on the NSI from the CE$\nu$NS experiments. Additionally, the
deviation of the measured value of the anomalous magnetic dipole moment of the
muon from the standard-model prediction can be fitted. The most limiting
constraints on our model come from the search for the decay of the new gauge
boson to $e^-e^+$ and invisible particles, carried out by NA48/2 and NA64,
respectively. We show that these bounds can be relaxed by opening up the decay
of the new gauge boson to new light scalars that eventually decay into the $e^-
e^+$ pairs. We show that there are ranges that can lead to both a solution to
the $(g - 2)_\mu$ anomaly and values of $\epsilon_{\mu \mu} = \epsilon_{\tau
\tau}$ large enough to be probed by future solar neutrino experiments.
- Diffuse Emission of Galactic High-Energy Neutrinos from a Global Fit of
Cosmic Rays
2211.15607 [abs] [pdf]
[abstract]
by Georg Schwefer, Philipp Mertsch, and Christopher Wiebusch.
In the standard picture of galactic cosmic rays, a diffuse flux of
high-energy gamma-rays and neutrinos is produced from inelastic collisions of
cosmic ray nuclei with the interstellar gas. The neutrino flux is a guaranteed
signal for high-energy neutrino observatories such as IceCube, but has not been
found yet. Experimental searches for this flux constitute an important test of
the standard picture of galactic cosmic rays. Both the observation and
non-observation would allow important implications for the physics of cosmic
ray acceleration and transport. We present CRINGE, a new model of galactic
diffuse high-energy gamma-rays and neutrinos, fitted to recent cosmic ray data
from AMS-02, DAMPE, IceTop as well as KASCADE. We quantify the uncertainties
for the predicted emission from the cosmic ray model, but also from the choice
of source distribution, gas maps and cross-sections. We consider the
possibility of a contribution from unresolved sources. Our model predictions
exhibit significant deviations from older models. Our fiducial model is
available at https://doi.org/10.5281/zenodo.7373010 .
- Physics implications of a combined analysis of COHERENT CsI and LAr data
2211.11905 [abs] [pdf]
[abstract]
by V. De Romeri, [and 5 more]O. G. Miranda, D. K. Papoulias, G. Sanchez Garcia, M. Tórtola, and J. W. F. Valle [hide authors].
The observation of coherent elastic neutrino nucleus scattering has opened
the window to many physics opportunities. This process has been measured by the
COHERENT Collaboration using two different targets, first CsI and then argon.
Recently, the COHERENT Collaboration has updated the CsI data analysis with a
higher statistics and an improved understanding of systematics. Here we perform
a detailed statistical analysis of the full CsI data and combine it with the
previous argon result. We discuss a vast array of implications, from tests of
the Standard Model to new physics probes. In our analyses we take into account
experimental uncertainties associated to the efficiency as well as the timing
distribution of neutrino fluxes, making our results rather robust. In
particular, we update previous measurements of the weak mixing angle and the
neutron root mean square charge radius for CsI and argon. We also update the
constraints on new physics scenarios including neutrino nonstandard
interactions and the most general case of neutrino generalized interactions, as
well as the possibility of light mediators. Finally, constraints on neutrino
electromagnetic properties are also examined, including the conversion to
sterile neutrino states. In many cases, the inclusion of the recent CsI data
leads to a dramatic improvement of bounds.
- Enhancing Sensitivity to Leptonic CP Violation using Complementarity
among DUNE, T2HK, and T2HKK
2211.10620 [abs] [pdf]
[abstract]
by Sanjib Kumar Agarwalla, [and 4 more]Sudipta Das, Alessio Giarnetti, Davide Meloni, and Masoom Singh [hide authors].
After the landmark discovery of non-zero $\theta_{13}$ by the modern reactor
experiments, unprecedented precision on neutrino mass-mixing parameters has
been achieved over the past decade. This has set the stage for the discovery of
leptonic CP violation (LCPV) at high confidence level in the next-generation
long-baseline neutrino oscillation experiments. In this work, we explore in
detail the possible complementarity among the on-axis DUNE and off-axis T2HK
experiments to enhance the sensitivity to LCPV suppressing the
$\theta_{23}-\delta_{\mathrm{CP}}$ degeneracy. We find that none of these
experiments individually can achieve the milestone of 3$\sigma$ LCPV for at
least 75% choices of $\delta_{\mathrm{CP}}$ in its entire range of
$[-180^{\circ} , 180^{\circ}]$, with their nominal exposures and systematic
uncertainties. However, their combination can attain the same for all values of
$\theta_{23}$ with only half of their nominal exposures. We observe that the
proposed T2HKK setup in combination with DUNE can further increase the CP
coverage to more than 80% with only half of their nominal exposures. We study
in detail how the coverage in $\delta_{\mathrm{CP}}$ for $\ge$ 3$\sigma$ LCPV
depends on the choice of $\theta_{23}$, exposure, optimal runtime in neutrino
and antineutrino modes, and systematic uncertainties in these experiments in
isolation and combination. We find that with an improved systematic uncertainty
of 2.7% in appearance mode, the standalone T2HK setup can provide a CP coverage
of around 75% for all values of $\theta_{23}$. We also discuss the pivotal role
of intrinsic, extrinsic, and total CP asymmetries in the appearance channel and
extrinsic CP asymmetries in the disappearance channel while analyzing our
results.
- Non-unitary three-neutrino mixing in the early Universe
2211.10522 [abs] [pdf]
[abstract]
by Stefano Gariazzo, [and 4 more]Pablo Martínez-Miravé, Olga Mena, Sergio Pastor, and Mariam Tórtola [hide authors].
Deviations from unitarity in the three-neutrino mixing canonical picture are
expected in many physics scenarios beyond the Standard Model. The mixing of new
heavy neutral leptons with the three light neutrinos would in principle modify
the strength and flavour structure of charged-current and neutral-current
interactions with matter. Non-unitarity effects would therefore have an impact
on the neutrino decoupling processes in the early Universe and on the value of
the effective number of neutrinos, $N_{\rm eff}$. We calculate the cosmological
energy density in the form of radiation with a non-unitary neutrino mixing
matrix, addressing the possible interplay between parameters. Highly accurate
measurements of $N_{\rm eff}$ from forthcoming cosmological observations can
provide independent and complementary limits on the departures from unitarity.
For completeness, we relate the scenario of small deviations from unitarity to
non-standard neutrino interactions and compare the forecasted constraints to
other existing limits in the literature.
- Strong cosmological constraints on the neutrino magnetic moment
2211.10432 [abs] [pdf]
[abstract]
by Pierluca Carenza, [and 4 more]Giuseppe Lucente, Martina Gerbino, Maurizio Giannotti, and Massimiliano Lattanzi [hide authors].
A sizable magnetic moment for neutrinos would be evidence of exotic physics.
In the early Universe, left-handed neutrinos with a magnetic moment would
interact with electromagnetic fields in the primordial plasma, flipping their
helicity and producing a population of right-handed (RH) neutrinos. In this
work, we present a new calculation of the production rate of RH neutrinos in a
multi-component primordial plasma and quantify their contribution to the total
energy density of relativistic species at early times, stressing the
implications of the dependence on the initial time for production. Our results
improve the previous cosmological limits by almost two orders of magnitudes.
Prospects for upcoming cosmological experiments are also discussed.
- Evidence for neutrino emission from the nearby active galaxy NGC 1068
2211.09972 [abs] [pdf]
[abstract]
by IceCube Collaboration, [and 385 more]R. Abbasi, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, J. M. Alameddine, C. Alispach, A. A. Alves Jr., N. M. Amin, K. Andeen, T. Anderson, G. Anton, C. Argüelles, Y. Ashida, S. Axani, X. Bai, A. Balagopal V., A. Barbano, S. W. Barwick, B. Bastian, V. Basu, S. Baur, R. Bay, J. J. Beatty, K. -H. Becker, J. Becker Tjus, C. Bellenghi, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, G. Binder, D. Bindig, E. Blaufuss, S. Blot, M. Boddenberg, F. Bontempo, J. Borowka, S. Böser, O. Botner, J. Böttcher, E. Bourbeau, F. Bradascio, J. Braun, B. Brinson, S. Bron, J. Brostean-Kaiser, S. Browne, A. Burgman, R. T. Burley, R. S. Busse, M. A. Campana, E. G. Carnie-Bronca, C. Chen, Z. Chen, D. Chirkin, K. Choi, B. A. Clark, K. Clark, L. Classen, A. Coleman, G. H. Collin, J. M. Conrad, P. Coppin, P. Correa, D. F. Cowen, R. Cross, C. Dappen, P. Dave, C. De Clercq, J. J. DeLaunay, D. Delgado López, H. Dembinski, K. Deoskar, A. Desai, P. Desiati, K. D. de Vries, G. de Wasseige, M. de With, T. DeYoung, A. Diaz, J. C. Díaz-Vélez, M. Dittmer, H. Dujmovic, M. Dunkman, M. A. DuVernois, E. Dvorak, T. Ehrhardt, P. Eller, R. Engel, H. Erpenbeck, J. Evans, P. A. Evenson, K. L. Fan, A. R. Fazely, A. Fedynitch, N. Feigl, S. Fiedlschuster, A. T. Fienberg, K. Filimonov, C. Finley, L. Fischer, D. Fox, A. Franckowiak, E. Friedman, A. Fritz, P. Fürst, T. K. Gaisser, J. Gallagher, E. Ganster, A. Garcia, S. Garrappa, L. Gerhardt, A. Ghadimi, C. Glaser, T. Glauch, T. Glüsenkamp, A. Goldschmidt, J. G. Gonzalez, S. Goswami, D. Grant, T. Grégoire, S. Griswold, C. Günther, P. Gutjahr, C. Haack, A. Hallgren, R. Halliday, L. Halve, F. Halzen, M. Ha Minh, K. Hanson, J. Hardin, A. A. Harnisch, A. Haungs, D. Hebecker, K. Helbing, F. Henningsen, E. C. Hettinger, S. Hickford, J. Hignight, C. Hill, G. C. Hill, K. D. Hoffman, R. Hoffmann, B. Hokanson-Fasig, K. Hoshina, F. Huang, M. Huber, T. Huber, K. Hultqvist, M. Hünnefeld, R. Hussain, K. Hymon, S. In, N. Iovine, A. Ishihara, M. Jansson, G. S. Japaridze, M. Jeong, M. Jin, B. J. P. Jones, D. Kang, W. Kang, X. Kang, A. Kappes, D. Kappesser, L. Kardum, T. Karg, M. Karl, A. Karle, U. Katz, M. Kauer, M. Kellermann, J. L. Kelley, A. Kheirandish, K. Kin, T. Kintscher, J. Kiryluk, S. R. Klein, R. Koirala, H. Kolanoski, T. Kontrimas, L. Köpke, C. Kopper, S. Kopper, D. J. Koskinen, P. Koundal, M. Kovacevich, M. Kowalski, T. Kozynets, E. Kun, N. Kurahashi, N. Lad, C. Lagunas Gualda, J. L. Lanfranchi, M. J. Larson, F. Lauber, J. P. Lazar, J. W. Lee, K. Leonard, A. Leszczyńska, Y. Li, M. Lincetto, Q. R. Liu, M. Liubarska, E. Lohfink, C. J. Lozano Mariscal, L. Lu, F. Lucarelli, A. Ludwig, W. Luszczak, Y. Lyu, W. Y. Ma, J. Madsen, K. B. M. Mahn, Y. Makino, S. Mancina, I. C. Mariş, I. Martinez-Soler, R. Maruyama, K. Mase, T. McElroy, F. McNally, J. V. Mead, K. Meagher, S. Mechbal, A. Medina, M. Meier, S. Meighen-Berger, J. Micallef, D. Mockler, T. Montaruli, R. W. Moore, R. Morse, M. Moulai, R. Naab, R. Nagai, R. Nahnhauer, U. Naumann, J. Necker, L. V. Nguyên, H. Niederhausen, M. U. Nisa, S. C. Nowicki, D. Nygren, A. Obertacke Pollmann, M. Oehler, B. Oeyen, A. Olivas, E. O'Sullivan, H. Pandya, D. V. Pankova, N. Park, G. K. Parker, E. N. Paudel, L. Paul, C. Pérez de los Heros, L. Peters, J. Peterson, S. Philippen, S. Pieper, M. Pittermann, A. Pizzuto, M. Plum, Y. Popovych, A. Porcelli, M. Prado Rodriguez, P. B. Price, B. Pries, G. T. Przybylski, C. Raab, J. Rack-Helleis, A. Raissi, M. Rameez, K. Rawlins, I. C. Rea, A. Rehman, P. Reichherzer, R. Reimann, G. Renzi, E. Resconi, S. Reusch, W. Rhode, M. Richman, B. Riedel, E. J. Roberts, S. Robertson, G. Roellinghoff, M. Rongen, C. Rott, T. Ruhe, D. Ryckbosch, D. Rysewyk Cantu, I. Safa, J. Saffer, S. E. Sanchez Herrera, A. Sandrock, J. Sandroos, M. Santander, S. Sarkar, S. Sarkar, K. Satalecka, M. Schaufel, H. Schieler, S. Schindler, T. Schmidt, A. Schneider, J. Schneider, F. G. Schröder, L. Schumacher, G. Schwefer, S. Sclafani, D. Seckel, S. Seunarine, A. Sharma, S. Shefali, M. Silva, B. Skrzypek, B. Smithers, R. Snihur, J. Soedingrekso, D. Soldin, C. Spannfellner, G. M. Spiczak, C. Spiering, J. Stachurska, M. Stamatikos, T. Stanev, R. Stein, J. Stettner, A. Steuer, T. Stezelberger, R. Stokstad, T. Stürwald, T. Stuttard, G. W. Sullivan, I. Taboada, S. Ter-Antonyan, S. Tilav, F. Tischbein, K. Tollefson, C. Tönnis, S. Toscano, D. Tosi, A. Trettin, M. Tselengidou, C. F. Tung, A. Turcati, R. Turcotte, C. F. Turley, J. P. Twagirayezu, B. Ty, M. A. Unland Elorrieta, N. Valtonen-Mattila, J. Vandenbroucke, N. van Eijndhoven, D. Vannerom, J. van Santen, S. Verpoest, C. Walck, T. B. Watson, C. Weaver, P. Weigel, A. Weindl, M. J. Weiss, J. Weldert, C. Wendt, J. Werthebach, M. Weyrauch, N. Whitehorn, C. H. Wiebusch, D. R. Williams, M. Wolf, K. Woschnagg, G. Wrede, J. Wulff, X. W. Xu, J. P. Yanez, S. Yoshida, S. Yu, T. Yuan, Z. Zhang, and P. Zhelnin [hide authors].
We report three searches for high energy neutrino emission from astrophysical
objects using data recorded with IceCube between 2011 and 2020. Improvements
over previous work include new neutrino reconstruction and data calibration
methods. In one search, the positions of 110 a priori selected gamma-ray
sources were analyzed individually for a possible surplus of neutrinos over
atmospheric and cosmic background expectations. We found an excess of
$79_{-20}^{+22}$ neutrinos associated with the nearby active galaxy NGC 1068 at
a significance of 4.2$\,\sigma$. The excess, which is spatially consistent with
the direction of the strongest clustering of neutrinos in the Northern Sky, is
interpreted as direct evidence of TeV neutrino emission from a nearby active
galaxy. The inferred flux exceeds the potential TeV gamma-ray flux by at least
one order of magnitude.
- Revisiting leptonic non-unitarity in light of FASER$ν$
2211.09638 [abs] [pdf]
[abstract]
by Daniel Aloni and Avital Dery.
In the presence of extra neutrino states at high scales, the low-energy
effective $3\times 3$ leptonic mixing matrix (LMM) is in general non-unitary.
We revisit the question of what is our current knowledge of individual LMM
matrix elements without assuming unitarity. We define two minimal sets of
experimental constraints -- direct $+$ inherent bounds and indirect bounds, and
analyze the implications of each set on leptonic non-unitarity. In addition, we
clarify the treatment of flux and cross-section predictions, taking into
account NP contamination in hadronic inputs. We use the currently running
FASER$\nu$ experiment as a case study in order to demonstrate the sensitivity
of collider neutrino experiments to leptonic non-unitarity. We find that
indirect bounds constrain LMM non-unitarity to below the $10^{-3}$ level,
stronger than current CKM non-unitarity constraints. Conversely, considering
only direct and inherent bounds we find that ${\cal O}(1)$ unitarity violation
is viable at $2\sigma$, and will be probed by the FASER$\nu$ experiment in the
current run of the LHC.
- Diffuse neutrino flux measurements with the Baikal-GVD neutrino
telescope
2211.09447 [abs] [pdf]
[abstract]
by Baikal Collaboration, [and 57 more]V. A. Allakhverdyan, A. D. Avrorin, A. V. Avrorin, V. M. Aynutdinov, Z. Bardačová, I. A. Belolaptikov, I. V. Borina, N. M. Budnev, V. Y. Dik, G. V. Domogatsky, A. A. Doroshenko, R. Dvornický, A. N. Dyachok, Zh. -A. M. Dzhilkibaev, E. Eckerová, T. V. Elzhov, L. Fajt, A. R. Gafarov, K. V. Golubkov, N. S. Gorshkov, T. I. Gress, K. G. Kebkal, V. K. Kebkal, A. Khatun, E. V. Khramov, M. M. Kolbin, K. V. Konischev, A. V. Korobchenko, A. P. Koshechkin, V. A. Kozhin, M. V. Kruglov, V. F. Kulepov, Y. M. Malyshkin, M. B. Milenin, R. R. Mirgazov, D. V. Naumov, V. Nazari, D. P. Petukhov, E. N. Pliskovsky, M. I. Rozanov, V. D. Rushay, E. V. Ryabov, G. B. Safronov, B. A. Shaybonov, D. Seitova, M. D. Shelepov, F. Šimkovic, A. E. Sirenko, A. V. Skurikhin, A. G. Solovjev, M. N. Sorokovikov, I. Štekl, A. P. Stromakov, O. V. Suvorova, V. A. Tabolenko, Y. V. Yablokova, and D. N. Zaborov [hide authors].
We report on the first observation of the diffuse cosmic neutrino flux with
the Baikal-GVD neutrino telescope. Using cascade-like events collected by
Baikal-GVD in 2018--2021, a significant excess of events over the expected
atmospheric background is observed. This excess is consistent with the
high-energy diffuse cosmic neutrino flux observed by IceCube. The null cosmic
flux assumption is rejected with a significance of 3.05$\sigma$. Assuming a
single power law model of the astrophysical neutrino flux with identical
contribution from each neutrino flavor, the following best-fit parameter values
are found: the spectral index $\gamma_{astro}$ = $2.58^{+0.27}_{-0.33}$ and the
flux normalization $\phi_{astro}$ = 3.04$^{+1.52}_{-1.21}$ per one flavor at
100 TeV.
- Revisiting pseudo-Dirac neutrino scenario after recent solar neutrino
data
2211.09105 [abs] [pdf]
[abstract]
by S. Ansarifard and Y. Farzan.
It is still unknown whether the mass terms for neutrinos are of Majorana type
or of Dirac type. An interesting possibility, known as pseudo-Dirac scheme
combines these two with a dominant Dirac mass term and a subdominant Majorana
one. As a result, the mass eigenstates come in pairs with a maximal mixing and
a small splitting determined by the Majorana mass. This will affect the
neutrino oscillation pattern for long baselines. We revisit this scenario
employing recent solar neutrino data, including the seasonal variation of the
$^7$Be flux recently reported by BOREXINO. We constrain the splitting using
these data and find that both the time integrated solar neutrino data and the
seasonal variation independently point towards a new pseudo-Dirac solution with
nonzero splitting for $\nu_2$ of $\Delta m_2^2\simeq 1.5\times 10^{-11}$
eV$^2$. We propose alternative methods to test this new solution. In
particular, we point out the importance of measuring the solar neutrino flux at
the intermediate energies $1.5~{\rm MeV}
- Entanglement in three-flavor collective neutrino oscillations
2211.07678 [abs] [pdf]
[abstract]
by Pooja Siwach, Anna M. Suliga, and A. Baha Balantekin.
Extreme conditions present in the interiors of the core-collapse supernovae
make neutrino-neutrino interactions not only feasible but dominant in specific
regions, leading to the non-linear evolution of the neutrino flavor. Results
obtained when such collective neutrino oscillations are treated in the
mean-field approximation deviate from the results using the many-body picture
because of the ignored quantum correlations. We present the first three flavor
many-body calculations of the collective neutrino oscillations. The
entanglement is quantified in terms of the entanglement entropy and the
components of the polarization vector. We propose a qualitative measure of
entanglement in terms of flavor-lepton number conserved quantities. We find
that in the cases considered in the present work, the entanglement can be
underestimated in two flavor approximation. The dependence of the entanglement
on mass ordering is also investigated. We also explore the mixing of mass
eigenstates in different mass orderings.
- Can ultralight dark matter explain the age-velocity dispersion relation
of the Milky Way disc: A revised and improved treatment
2211.07452 [abs] [pdf]
[abstract]
by Barry T. Chiang, Jeremiah P. Ostriker, and Hsi-Yu Schive.
Ultralight axion-like particles $m_a \sim 10^{-22}$ eV, or Fuzzy Dark Matter
(FDM), behave comparably to cold dark matter (CDM) on cosmological scales and
exhibit a kpc-size de Broglie wavelength capable of alleviating established
(sub-)galactic-scale problems of CDM. Substructures inside an FDM halo incur
gravitational potential perturbations, resulting in stellar heating sufficient
to account for the Galactic disc thickening over a Hubble time, as first
demonstrated by Church et al. We present a more sophisticated treatment that
incorporates the full baryon and dark matter distributions of the Milky Way and
adopts stellar disc kinematics inferred from recent Gaia, APOGEE, and LAMOST
surveys. Ubiquitous density granulation and subhalo passages respectively drive
inner disc thickening and flaring of the outer disc, resulting in an
observationally consistent `U-shaped' disc vertical velocity dispersion profile
with the global minimum located near the solar radius. The observed
age-velocity dispersion relation in the solar vicinity can be explained by the
FDM-substructure-induced heating and places an exclusion bound $m_a \gtrsim
0.4\times10^{-22}$ eV. We assess non-trivial uncertainties in the empirical
core-halo relation, FDM subhalo mass function and tidal stripping, and stellar
heating estimate. The mass range $m_a\simeq 0.5-0.7\times10^{-22}$ eV favoured
by the observed thick disc kinematics is in tension with several exclusion
bounds inferred from dwarf density profiles, stellar streams, and Milky Way
satellite populations, which could be significantly relaxed due to the
aforesaid uncertainties. Additionally, strongly anisotropic heating could help
explain the formation of ultra-thin disc galaxies.
- Wilks's Theorem, Global Fits, and Neutrino Oscillations
2211.06347 [abs] [pdf]
[abstract]
by J. M. Hardin.
Tests of models for new physics appearing in neutrino experiments often
involve global fits to a quantum mechanical effect called neutrino
oscillations. This paper introduces students to methods commonly used in these
global fits starting from an understanding of more conventional fitting methods
using log-likelihood and $\chi^2$ minimization. Specifically, we discuss how
the $\Delta\chi^2$, which compares the $\chi^2$ of the fit with the new physics
to the $\chi^2$ of the Standard Model prediction, is often interpreted using
Wilks's theorem. This paper uses toy models to explore the properties of
$\Delta\chi^2$ as a test statistic for oscillating functions. The statistics of
such models are shown to deviate from Wilks's theorem. Tests for new physics
also often examine data subsets for ``tension'' called the ``parameter goodness
of fit''. In this paper, we explain this approach and use toy models to examine
the validity of the probabilities from this test also. Although we have chosen
a specific scenario -- neutrino oscillations -- to illustrate important points,
students should keep in mind that these points are widely applicable when
fitting multiple data sets to complex functions.
- Studying neutrino oscillations at DUNE through dynamical Lorentz
symmetry breaking in four-Majorana fermion model
2211.06192 [abs] [pdf]
[abstract]
by Susie Kim.
We study the impact of the dynamical Lorentz symmetry breaking induced by the
auxiliary gauge fields of neutrino on the oscillations probability at DUNE. The
DLSB introduces an alternative energy-momentum relation of the neutrinos and
thus results in a new oscillation probability. We extend the previously
proposed four-Majorana fermion model that gives rise to DLSB after the type II
seesaw mechanism by considering the electron neutrino forward scattering when
passing through a medium. Moreover, we incorporate the three-flavor neutrino
states, which introduce the CP-violation term inside the oscillation
probability. The impact of DLSB parameters around the order of
$10^{-2}-10^{-3}$, which are at a strong coupling regime, on the oscillation
probability is found to be measurable at DUNE within the 20 years through
$\nu_e$ and $\overline{\nu}_e$ disappearance signals. We also compare the
predicted spectra of the DLSB oscillations and the oscillation with the
CP-violating term equal to $\pi/2$ to conclude that the presence of DLSB would
increase the systematic uncertainty for the measurement of CP-violation at
DUNE.
- Updated constraints on sterile neutrino mixing in the OPERA experiment
using a new $ν_e$ identification method
2211.04636 [abs] [pdf]
[abstract]
by N. Agafonova, [and 125 more]A. Alexandrov, A. Anokhina, S. Aoki, A. Ariga, T. Ariga, A. Bertolin, C. Bozza, R. Brugnera, S. Buontempo, M. Chernyavskiy, A. Chukanov, L. Consiglio, N. D'Ambrosio, G. De Lellis, M. De Serio, P. del Amo Sanchez, A. Di Crescenzo, D. Di Ferdinando, N. Di Marco, S. Dmitrievsky, M. Dracos, D. Duchesneau, S. Dusini, T. Dzhatdoev, J. Ebert, A. Ereditato, R. A. Fini, T. Fukuda, G. Galati, A. Garfagnini, V. Gentile, J. Goldberg, S. Gorbunov, Y. Gornushkin, G. Grella, A. M. Guler, C. Gustavino, C. Hagner, T. Hara, T. Hayakawa, A. Hollnagel, K. Ishiguro, A. Iuliano, K. Jakovcic, C. Jollet, C. Kamiscioglu, M. Kamiscioglu, S. H. Kim, N. Kitagawa, B. Klicek, K. Kodama, M. Komatsu, U. Kose, I. Kreslo, F. Laudisio, A. Lauria, A. Longhin, P. Loverre, A. Malgin, G. Mandrioli, T. Matsuo, V. Matveev, N. Mauri, E. Medinaceli, A. Meregaglia, S. Mikado, M. Miyanishi, F. Mizutani, P. Monacelli, M. C. Montesi, K. Morishima, M. T. Muciaccia, N. Naganawa, T. Naka, M. Nakamura, T. Nakano, K. Niwa, S. Ogawa, N. Okateva, K. Ozaki, A. Paoloni, L. Paparella, B. D. Park, L. Pasqualini, A. Pastore, L. Patrizii, H. Pessard, D. Podgrudkov, N. Polukhina, M. Pozzato, F. Pupilli, M. Roda, T. Roganova, H. Rokujo, G. Rosa, O. Ryazhskaya, O. Sato, A. Schembri, I. Shakiryanova, T. Shchedrina, E. Shibayama, H. Shibuya, T. Shiraishi, S. Simone, C. Sirignano, G. Sirri, A. Sotnikov, M. Spinetti, L. Stanco, N. Starkov, S. M. Stellacci, M. Stipcevic, P. Strolin, S. Takahashi, M. Tenti, F. Terranova, V. Tioukov, S. Tufanli, S. Vasina, P. Vilain, E. Voevodina, L. Votano, J. L. Vuilleumier, G. Wilquet, and C. S. Yoon [hide authors].
This paper describes a new $\nu_e$ identification method specifically
designed to improve the low-energy ($< 30\,\mathrm{GeV}$) $\nu_e$
identification efficiency attained by enlarging the emulsion film scanning
volume with the next generation emulsion readout system. A relative increase of
25-70% in the $\nu_e$ low-energy region is expected, leading to improvements in
the OPERA sensitivity to neutrino oscillations in the framework of the 3 + 1
model. The method is applied to a subset of data where the detection efficiency
increase is expected to be more relevant, and one additional $\nu_e$ candidate
is found. The analysis combined with the $\nu_\tau$ appearance results improves
the upper limit on $\sin^2 2\theta_{\mu e}$ to 0.016 at 90% C.L. in the
MiniBooNE allowed region $\Delta m^2_{41} \sim 0.3\,\mathrm{eV}^2$.
- The ngEHT's Role in Measuring Supermassive Black Hole Spins
2211.03910 [abs] [pdf]
[abstract]
by Angelo Ricarte, [and 4 more]Paul Tiede, Razieh Emami, Aditya Tamar, and Priyamvada Natarajan [hide authors].
While supermassive black hole masses have been cataloged across cosmic time,
only a few dozen of them have robust spin measurements. By extending and
improving the existing Event Horizon Telescope (EHT) array, the next-generation
Event Horizon Telescope (ngEHT) will enable multifrequency, polarimetric movies
on event horizon scales, which will place new constraints on the space-time and
accretion flow. By combining this information, it is anticipated that the ngEHT
may be able to measure tens of supermassive black hole masses and spins. In
this white paper, we discuss existing spin measurements and many proposed
techniques with which the ngEHT could potentially measure spins of target
supermassive black holes. Spins measured by the ngEHT would represent a
completely new sample of sources that, unlike pre-existing samples, would not
be biased towards objects with high accretion rates. Such a sample would
provide new insights into the accretion, feedback, and cosmic assembly of
supermassive black holes.
- γ-Ray and ultra-high energy neutrino background suppression due
to solar radiation
2211.03807 [abs] [pdf]
[abstract]
by Shyam Balaji.
The Sun emits copious amounts of photons and neutrinos in an approximately
spatially isotropic distribution. Diffuse $\gamma$-rays and ultra-high energy
(UHE) neutrinos from extragalactic sources may subsequently interact and
annihilate with the emitted solar photons and neutrinos respectively. This will
in turn induce an anisotropy in the cosmic ray (CR) background due to
attenuation of the $\gamma$-ray and UHE neutrino flux by the solar radiation.
Measuring this reduction, therefore, presents a simple and powerful
astrophysical probe of electroweak interactions. In this letter we compute such
anisotropies for TeV $\gamma$-rays, which at the Earth (Sun) can be at least
$\simeq 10^{-4},(10^{-2})$. The optical depth at Earth for elongation angles
more focused around the Sun ($\lesssim 10^\circ$), can be around $10^{-3}$ and
larger. Neutrino attenuation is extremely tiny for for PeV scale UHE neutrinos.
We briefly discuss observational prospects for experiments such as the Fermi
Gamma-Ray Space Telescope Large Area Telescope (Fermi LAT), High-Altitude Water
Cherenkov (HAWC) detector, The Large High Altitude Air Shower Observatory
(LHAASO), Cherenkov Telescope Array (CTA) and IceCube. The potential for
measuring $\gamma$-ray attenuation at orbital locations of other active
satellites such as the Parker Solar Probe and James Webb Space Telescope (JWST)
is also explored.
- Sterile Neutrinos: Propagation in Matter and Sensitivity to Sterile Mass
Ordering
2211.03473 [abs] [pdf]
[abstract]
by Dibya S. Chattopadhyay, [and 5 more]Moon Moon Devi, Amol Dighe, Debajyoti Dutta, Dipyaman Pramanik, and Sushant K. Raut [hide authors].
We analytically calculate the neutrino conversion probability $P_{\mu e}$ in
the presence of sterile neutrinos, with exact dependence on $\Delta m^2_{41}$
and with matter effects explicitly included. Using perturbative expansion in
small parameters, the terms involving the small mixing angles $\theta_{24}$ and
$\theta_{34}$ can be separated out, with $\theta_{34}$ dependence only arising
due to matter effects. We express $P_{\mu e}$ in terms of the quantities of the
form $\sin(x)/x$, which helps in elucidating its dependence on matter effects
and a wide range of $\Delta m^2_{41}$ values. Our analytic expressions allow us
to predict the effects of the sign of $\Delta m^2_{41}$ at a long baseline
experiment like DUNE. We numerically calculate the sensitivity of DUNE to the
sterile mass ordering and find that this sensitivity can be significant in the
range $|\Delta m^2_{41}| \sim (10^{-4} - 10^{-2})$ eV$^2$, for either mass
ordering of active neutrinos. The dependence of this sensitivity on the value
of $\Delta m^2_{41}$ for all mass ordering combinations can be explained by
investigating the resonance-like terms appearing due to the interplay between
the sterile sector and matter effects.
- Measuring Oscillations with A Million Atmospheric Neutrinos
2211.02666 [abs] [pdf]
[abstract]
by C. A. Argüelles, [and 3 more]P. Fernández, I. Martínez-Soler, and M. Jin [hide authors].
We analyze the expected sensitivity of current and near-future
water(ice)-Cherenkov atmospheric neutrino experiments in the context of
standard three-flavor neutrinos oscillations. In this first in-depth combined
atmospheric neutrino analysis, we analyze the current shared systematic
uncertainties arising from the shared flux and neutrino-water interactions. We
then implement the systematic uncertainties of each experiment in detail and
develop the atmospheric neutrino simulations for Super-Kamiokande (SK), with
and without neutron-tagging capabilities (including SuperK-Gd),
IceCube-Upgrade, and ORCA detectors. We carefully review the synergies and
features of these experiments to examine the potential of a joint analysis of
these atmospheric neutrino data in resolving the $\theta_{23}$ octant at 99\%
C.L. and determining the neutrino mass ordering above 5$\sigma$ by 2030.
Additionally, we assess the capability to constraint $\theta_{13}$ and the
CP-violating phase ($\delta_{CP}$) in the leptonic sector independently from
reactor and accelerator neutrino data, providing vital information for
next-generation neutrino oscillation experiments such as DUNE and
Hyper-Kamiokande.
- New Clues About Light Sterile Neutrinos: Preference for Models with
Damping Effects in Global Fits
2211.02610 [abs] [pdf]
[abstract]
by J. M. Hardin, [and 7 more]I. Martinez-Soler, A. Diaz, M. Jin, N. W. Kamp, C. A. Argüelles, J. M. Conrad, and M. H. Shaevitz [hide authors].
This article reports global fits of short-baseline neutrino data to
oscillation models involving light sterile neutrinos. In the commonly-used 3+1
plane wave model, there is a well-known 4.9$\sigma$ tension between data sets
sensitive to appearance versus disappearance of neutrinos. We find that models
that damp the oscillation prediction for the reactor data sets, especially at
low energy, substantially improve the fits and reduce the tension. We consider
two such scenarios. The first scenario introduces the quantum mechanical
wavepacket effect that accounts for the source size in reactor experiments into
the 3+1 model. We find that inclusion of the wavepacket effect greatly improves
the overall fit compared to a 3$\nu$ model by $\Delta \chi^2/$DOF$=61.1/4$
($7.1\sigma$ improvement) with best-fit $\Delta m^2=1.4$ eV$^2$ and wavepacket
length of 67fm. The internal tension is reduced to 3.4$\sigma$. If reactor-data
only is fit, then the wavepacket preferred length is 91 fm ($>20$ fm at 99\%
CL). The second model introduces oscillations involving sterile flavor and
allows the decay of the heaviest, mostly sterile mass state, $\nu_4$. This
model introduces a damping term similar to the wavepacket effect, but across
all experiments. Compared to a three-neutrino fit, this has a $\Delta
\chi^2/$DOF$=60.6/4$ ($7\sigma$ improvement) with preferred $\Delta m^2=1.4$
eV$^2$ and decay $\Gamma = 0.35$ eV$^2$. The internal tension is reduced to
3.7$\sigma$.
For many years, the reactor event rates have been observed to have structure
that deviates from prediction. Community discussion has focused on an excess
compared to prediction observed at 5 MeV; however, other deviations are
apparent. This structure has $L$ dependence that is well-fit by the damped
models. Before assuming this points to new physics, we urge closer examination
of systematic effects that could lead to this $L$ dependence.
- Neutrino Origin of LHAASO's 18 TeV GRB221009A Photon
2211.02028 [abs] [pdf]
[abstract]
by Vedran Brdar and Ying-Ying Li.
LHAASO collaboration detected photons with energy above 10 TeV from the most
recent gamma-ray burst (GRB), GRB221009A. Given the redshift of this event,
$z\sim 0.15$, photons of such energy are expected to interact with the diffuse
extragalactic background light (EBL) well before reaching Earth. In this paper
we provide a novel neutrino-related explanation of the most energetic 18 TeV
event reported by LHAASO. We find that the minimal viable scenario involves
both mixing and transition magnetic moment portal between light and sterile
neutrinos. The production of sterile neutrinos occurs efficiently via mixing
while the transition magnetic moment portal governs the decay rate in the
parameter space where tree-level decays via mixing to non-photon final states
are suppressed. Our explanation of this event, while being consistent with the
terrestrial constraints, points to the non-standard cosmology.
- On ALP scenarios and GRB 221009A
2211.02010 [abs] [pdf]
[abstract]
by Pierluca Carenza and M. C. David Marsh.
The extraordinarily bright gamma-ray burst GRB 221009A was observed by a
large number of observatories, from radio frequencies to gamma-rays. Of
particular interest are the reported observations of photon-like air showers of
very high energy: an 18 TeV event in LHAASO and a 251 TeV event at Carpet-2.
Gamma rays at these energies are expected to be absorbed by pair-production
events on background photons when travelling intergalactic distances. Several
works have sought to explain the observations of these events, assuming they
originate from GRB 221009A, by invoking axion-like particles (ALPs). We
reconsider this scenario and account for astrophysical uncertainties due to
poorly known magnetic fields and background photon densities. We find that,
robustly, the ALP scenario cannot simultaneously account for an 18 TeV and a
251 TeV photon from GRB 221009A.
- Study of light sterile neutrino at the long-baseline experiment options
at KM3NeT
2211.01816 [abs] [pdf]
[abstract]
by Dinesh Kumar Singha, [and 3 more]Monojit Ghosh, Rudra Majhi, and Rukmani Mohanta [hide authors].
In this paper, we study the capability of different long-baseline experiment
options at the KM3NeT facility i.e., P2O, Upgraded P2O and P2SO to probe the
light sterile neutrino and compare their sensitivities with DUNE. The P2O
option will have neutrinos from a 90 KW beam at Protvino to be detected at the
ORCA detector, the Upgraded P2O will have neutrinos from the upgraded 450 KW
beam to be detected at the ORCA detector and the option P2SO will have
neutrinos from a 450 KW beam to be detected at the upgraded Super-ORCA
detector. All these options will have a baseline around 2595 km. Our results
show that the experiments at the KM3NeT (DUNE) would be more sensitive if the
value of $\Delta m^2_{41}$ is around 10 (1) eV$^2$. Our results also show that
the role of near detector is very important for the study of sterile neutrinos
and addition of near detector improves the sensitivity as compared to only far
detector for 3+1 scenario. Among the three options at KM3NeT, the sensitivity
of P2O and upgraded P2O is limited and sensitivity of P2SO is either comparable
or better than DUNE.
- A seesaw model for large neutrino masses in concordance with cosmology
2211.01729 [abs] [pdf]
[abstract]
by Miguel Escudero, Thomas Schwetz, and Jorge Terol-Calvo.
Cosmological constraints on the sum of the neutrino masses can be relaxed if
the number density of active neutrinos is reduced compared to the standard
scenario, while at the same time keeping the effective number of neutrino
species $N_{\rm eff}\approx 3$ by introducing a new component of dark
radiation. We discuss a UV complete model to realise this idea, which
simultaneously provides neutrino masses via the seesaw mechanism. It is based
on a $U(1)$ symmetry in the dark sector, which can be either gauged or global.
In addition to heavy seesaw neutrinos, we need to introduce $\mathcal{O}(10)$
generations of massless sterile neutrinos providing the dark radiation. Then we
can accommodate active neutrino masses with $\sum m_\nu \sim 1$ eV, in the
sensitivity range of the KATRIN experiment. We discuss the phenomenology of the
model and identify the allowed parameter space. We argue that the gauged
version of the model is preferred, and in this case the typical energy scale of
the model is in the 10 MeV to few GeV range.
- GRB 221009A Gamma Rays from Radiative Decay of Heavy Neutrinos?
2211.00634 [abs] [pdf]
[abstract]
by Alexei Y. Smirnov and Andreas Trautner.
We consider a mechanism which allows to decrease attenuation of high energy
gamma ray flux from gamma ray burst GRB 221009A. The mechanism is based on the
existence of a heavy $m_N\sim0.1\,\mathrm{MeV}$ mostly sterile neutrino $N$
which mixes with active neutrinos. $N$'s are produced in GRB in $\pi$ and $K$
decays via mixing with $\nu_\mu$. They undergo the radiative decay
$N\rightarrow \nu \gamma$ on the way to the Earth. The usual exponential
attenuation of gamma rays is lifted to an attenuation inverse in the optical
depth. Various restrictions on this scenario are discussed. We find that the
high energy $\gamma$ events at $18\,\mathrm{TeV}$ and potentially
$251\,\mathrm{TeV}$ can be explained if (i) the GRB active neutrino fluence is
close to the observed limit, (ii) the branching ratio of $N\rightarrow \nu
\gamma$ is at least of the order 10%.
- Probe the Mixing Parameter $|V_{τN}|^2$ for Heavy Neutrinos
2211.00309 [abs] [pdf]
[abstract]
by Lingxiao Bai, Ying-nan Mao, and Kechen Wang.
Because of the difficulty in detecting final state taus, the mixing parameter
$|V_{\tau N}|^2$ for heavy neutrino $N$ is not well studied at current
experiments, compared with other mixing parameters $|V_{e N}|^2$ and $|V_{\mu
N}|^2$. In this paper, we focus on a challenging scenario where $N$ mixes with
active neutrino of tau flavour only, i.e. $ |V_{\tau N}|^2 \neq 0 $ and $|V_{e
N}|^2 = |V_{\mu N}|^2 = 0$. We derive current constraints on $|V_{\tau N}|^2$
from the rare $Z$-boson decay and electroweak precision data (EWPD). To
forecast the future limits, we also investigate the signal $p p \to \tau^{\pm}
\tau^{\pm} j j $ via a Majorana heavy neutrino at future proton-proton
colliders. To suppress the background, both taus are required to decay
leptonically into muons, leading to the final state containing two same sign
muons, at least two jets plus moderate missing energy. The signal and relevant
background processes are simulated at the HL-LHC and SppC/FCC-hh with
center-of-mass energy of 14 TeV and 100 TeV. The preselection and multivariate
analyses based on machine-learning are performed to reduce background. Limits
on $|V_{\tau N}|^2$ are shown for heavy neutrino mass in the range 10-1000 GeV
based on measurements from the rare $Z$-boson decay and EWPD, and searches at
the HL-LHC and SppC/FCC-hh with integrated luminosities of 3 and 20 ab$^{-1}$.
October 2022
- Neutrinos from the Brightest Gamma-Ray Burst?
2210.15625 [abs] [pdf]
[abstract]
by Kohta Murase, [and 4 more]Mainak Mukhopadhyay, Ali Kheirandish, Shigeo S. Kimura, and Ke Fang [hide authors].
We discuss implications that can be obtained by searches for neutrinos from
the brightest gamma-ray burst, GRB 221009A. We derive constraints on GRB model
parameters such as the cosmic-ray loading factor and dissipation radius, taking
into account both neutrino spectra and effective areas. The results are strong
enough to constrain proton acceleration near the photosphere, and we find that
the single burst limits are comparable to those from stacking analysis.
Quasithermal neutrinos from subphotospheres and ultrahigh-energy neutrinos from
external shocks are not yet constrained. We show that GeV-TeV neutrinos
originating from neutron collisions are detectable, and urge dedicated analysis
on these neutrinos with DeepCore and IceCube as well as ORCA and KM3NeT.
- NaNu: Proposal for a Neutrino Experiment at the SPS Collider located at
the North Area of CERN
2210.15532 [abs] [pdf]
[abstract]
by Friedemann Neuhaus, [and 3 more]Matthias Schott, Chen Wang, and Rainer Wanke [hide authors].
Several experiments have been proposed in the recent years to study the
nature of tau neutrinos, in particular aiming for a first observation of tau
anti-neutrinos, more stringent upper limit on its anomalous magnetic moment as
well as new constrains on the strange-quark content of the nucleon. We propose
here a new low-cost neutrino experiment at the CERN North area, named NaNu
(North Area NeUtrino), compatible with the realization of the future SHADOWS
and HIKE experiments at the same experimental area.
- A Significant Sudden Ionospheric Disturbance associated with Gamma-Ray
Burst GRB 221009A
2210.15284 [abs] [pdf]
[abstract]
by Laura A. Hayes and Peter T. Gallagher.
We report the detection of a significant ionospheric disturbance in the
D-region of Earth's ionosphere which was associated with the massive gamma-ray
burst GRB 221009A that occurred on October 9 2022. We identified the
disturbance over northern Europe - a result of the increased ionisation by X-
and gamma-ray emission from the GRB - using very low frequency (VLF) radio
waves as a probe of the D-region. These observations demonstrate that an
extra-galactic GRB can have a significant impact on the terrestrial ionosphere
and illustrates that the Earth's ionosphere can be used as a giant X- and
gamma-ray detector. Indeed, these observations may provide insights into the
impacts of GRBs on the ionospheres of planets in our solar system and beyond.
- Neutral-current neutrino cross section and expected supernova signals
for $^{40}$Ar from a three-fold increase in the magnetic dipole strength
2210.14316 [abs] [pdf]
[abstract]
by W. Tornow, [and 7 more]A. P. Tonchev, S. W. Finch, Krishichayan, X. B. Wang, A. C. Hayes, H. G. D. Yeomans, and D. A. Newmark [hide authors].
In view of the great interest in liquid argon neutrino detectors, the
$^{40}$Ar($\gamma,\gamma'$)$^{40}$Ar$^{*}$ reaction was revisited to guide a
calculation of the neutral current neutrino cross section at supernova
energies. Using the nuclear resonance fluorescence technique with a
monoenergetic, 99% linearly polarized photon beam, we report a three-fold
increase in magnetic dipole strength at around 10 MeV in $^{40}$Ar. Based on
shell-model calculations, and using the experimentally identified transitions,
the neutral current neutrino cross sections for low-energy reactions on
$^{40}$Ar are calculated.
- The Role of a Heavy Neutrino in the Gamma-Ray Burst GRB-221009A
2210.14178 [abs] [pdf]
[abstract]
by Kingman Cheung.
Recently, several telescopes, including Swift-BAT, GBM, and LHAASO, have
observed the ever highest-energy and long-duration gamma-rays from a gamma-ray
burst named as GRB221009A (located at a red-shift of $z=0.151$) on October 9,
2022. Conventional understanding tells us that very high-energy photons
produced at such a far distance suffer severe attenuation before reaching the
Earth. We propose the existence of a sub-MeV to $O(10)$ MeV heavy neutrino with
a transitional magnetic dipole moment, via which the heavy neutrino is produced
at the GRB. It then travels a long distance to our galaxy and decays into a
neutrino and a photon, which is observed. In such a way, the original
high-energy photon produced at the GRB can survive long-distance attenuation.
- Stringent constraint on CPT violation with the synergy of T2K-II,
NO$ν$A extension, and JUNO
2210.13044 [abs] [pdf]
[abstract]
by T. V. Ngoc, [and 3 more]S. Cao, N. T. Hong Van, and P. T. Quyen [hide authors].
Neutrino oscillation experiments have measured precisely the mass-squared
differences of three neutrino mass eigenstates, and three leptonic mixing
angles by utilizing both neutrino and anti-neutrino oscillations. The possible
CPT violation may manifest itself in the difference of neutrino and
anti-neutrino oscillation parameters, making these experiments promising tools
for testing CPT invariance. We investigate empirically the sensitivity of the
CPT test via the difference in mass-squared splittings ($\Delta m^2_{31} -
\Delta \overline{m}^2_{31}$) and in leptonic mixing angles ($\sin^2\theta_{23}
- \sin^2\overline{\theta}_{23}$) with the synergy of T2K-II, NO$\nu$A
extension, and JUNO experiments. If the CPT symmetry is found to be conserved,
the joint analysis of the three experiments will be able to establish limits of
$|\Delta m^2_{31} - \Delta \overline{m}^2_{31}|$ < $5.3\times 10^{-3}
\text{eV}^2$ and $|\sin^2\theta_{23} - \sin^2\overline{\theta}_{23}|$ < $0.10$
at 3$\sigma$ C. L. on the possible CPT violation. We find that with ($\Delta
m^2_{31} - \Delta \overline{m}^2_{31}$), the dependence of the statistical
significance on the relevant parameters to exclude the CPT conservation is
marginal, and that, if the difference in the best-fit values of $\Delta
m^2_{31}$ and $\Delta \overline{m}^2_{31}$ measured by MINOS(+) and NO$\nu$A
persists as the true, the combined analysis will rule out the CPT conservation
at 4$\sigma$ C. L.. With the ($\sin^2\theta_{23} -
\sin^2\overline{\theta}_{23}$), the statistical significance to exclude CPT
invariance depends strongly on the true value of
$\theta_{23}(\overline{\theta}_{23})$. In case of maximal mixing of
$\theta_{23}$, the CPT conservation will be excluded at 3$\sigma$ C. L. or more
if the difference in the best-fit values of $\theta_{23}$ and
$\overline{\theta}_{23}$ remains as the true.
- Searching for neutrinos from solar flares across solar cycles 23 and 24
with the Super-Kamiokande detector
2210.12948 [abs] [pdf]
[abstract]
by K. Okamoto, [and 244 more]K. Abe, Y. Hayato, K. Hiraide, K. Hosokawa, K. Ieki, M. Ikeda, J. Kameda, Y. Kanemura, Y. Kaneshima, Y. Kataoka, Y. Kashiwagi, S. Miki, S. Mine, M. Miura, S. Moriyama, Y. Nagao, M. Nakahata, Y. Nakano, S. Nakayama, Y. Noguchi, K. Sato, H. Sekiya, K. Shimizu, M. Shiozawa, H. Shiba, Y. Sonoda, Y. Suzuki, A. Takeda, Y. Takemoto, A. Takenaka, H. Tanaka, S. Watanabe, T. Yano, S. Han, T. Kajita, K. Okumura, T. Tashiro, T. Tomiya, X. Wang, J. Xia, S. Yoshida, G. D. Megias, P. Fernandez, L. Labarga, N. Ospina, B. Zaldivar, B. W. Pointon, E. Kearns, J. L. Raaf, L. Wan, T. Wester, J. Bian, N. J. Griskevich, W. R. Kropp, S. Locke, M. B. Smy, H. W. Sobel, V. Takhistov, A. Yankelevich, J. Hill, J. Y. Kim, S. H. Lee, I. T. Lim, D. H. Moon, R. G. Park, B. Bodur, K. Scholberg, C. W. Walter, A. Beauchene, L. Bernard, A. Coffani, O. Drapier, S. El Hedri, A. Giampaolo, Th. A. Mueller, A. D. Santos, P. Paganini, B. Quilain, T. Ishizuka, T. Nakamura, J. S. Jang, J. G. Learned, K. Choi, S. Cao, L. H. V. Anthony, D. Martin, M. Scott, A. A. Sztuc, Y. Uchida, V. Berardi, M. G. Catanesi, E. Radicioni, N. F. Calabria, L. N. Machado, G. De Rosa, G. Collazuol, F. Iacob, M. Lamoureux, M. Mattiazzi, L. Ludovici, M. Gonin, G. Pronost, C. Fujisawa, Y. Maekawa, Y. Nishimura, M. Friend, T. Hasegawa, T. Ishida, T. Kobayashi, M. Jakkapu, T. Matsubara, T. Nakadaira, K. Nakamura, Y. Oyama, K. Sakashita, T. Sekiguchi, T. Tsukamoto, N. Bhuiyan, T. Boschi, G. T. Burton, F. Di Lodovico, J. Gao, A. Goldsack, T. Katori, J. Migenda, M. Taani, Z. Xie, S. Zsoldos, Y. Kotsar, H. Ozaki, A. T. Suzuki, Y. Takeuchi, S. Yamamoto, C. Bronner, J. Feng, T. Kikawa, M. Mori, T. Nakaya, R. A. Wendell, K. Yasutome, S. J. Jenkins, N. McCauley, P. Mehta, A. Tarrant, K. M. Tsui, Y. Fukuda, Y. Itow, H. Menjo, K. Ninomiya, J. Lagoda, S. M. Lakshmi, M. Mandal, P. Mijakowski, Y. S. Prabhu, J. Zalipska, M. Jia, J. Jiang, C. K. Jung, C. Vilela, M. J. Wilking, C. Yanagisawa, M. Harada, H. Ishino, S. Ito, H. Kitagawa, Y. Koshio, W. Ma, F. Nakanishi, N. Piplani, S. Sakai, G. Barr, D. Barrow, L. Cook, S. Samani, D. Wark, A. Holin, F. Nova, J. Y. Yang, J. E. P. Fannon, M. Malek, J. M. McElwee, O. Stone, M. D. Thiesse, L. F. Thompson, H. Okazawa, S. B. Kim, E. Kwon, J. W. Seo, I. Yu, A. K. Ichikawa, K. D. Nakamura, S. Tairafune, K. Nishijima, M. Koshiba, K. Iwamoto, K. Nakagiri, Y. Nakajima, S. Shima, N. Taniuchi, M. Yokoyama, K. Martens, P. de Perio, M. R. Vagins, M. Kuze, S. Izumiyama, M. Inomoto, M. Ishitsuka, H. Ito, T. Kinoshita, R. Matsumoto, Y. Ommura, N. Shigeta, M. Shinoki, T. Suganuma, K. Yamauchi, J. F. Martin, H. A. Tanaka, T. Towstego, R. Akutsu, R. Gaur, V. Gousy-Leblanc, M. Hartz, A. Konaka, X. Li, N. W. Prouse, S. Chen, B. D. Xu, B. Zhang, M. Posiadala-Zezula, S. B. Boyd, D. Hadley, M. Nicholson, M. O'Flaherty, B. Richards, A. Ali, B. Jamieson, J. Walker, Ll. Marti, A. Minamino, G. Pintaudi, S. Sano, R. Sasaki, S. Suzuki, and K. Wada [hide authors].
Neutrinos associated with solar flares (solar-flare neutrinos) provide
information on particle acceleration mechanisms during the impulsive phase of
solar flares. We searched using the Super-Kamiokande detector for neutrinos
from solar flares that occurred during solar cycles $23$ and $24$, including
the largest solar flare (X28.0) on November 4th, 2003. In order to minimize the
background rate we searched for neutrino interactions within narrow time
windows coincident with $\gamma$-rays and soft X-rays recorded by satellites.
In addition, we performed the first attempt to search for solar-flare neutrinos
from solar flares on the invisible side of the Sun by using the emission time
of coronal mass ejections (CMEs). By selecting twenty powerful solar flares
above X5.0 on the visible side and eight CMEs whose emission speed exceeds
$2000$ $\mathrm{km \, s^{-1}}$ on the invisible side from 1996 to 2018, we
found two (six) neutrino events coincident with solar flares occurring on the
visible (invisible) side of the Sun, with a typical background rate of $0.10$
($0.62$) events per flare in the MeV-GeV energy range. No significant
solar-flare neutrino signal above the estimated background rate was observed.
As a result we set the following upper limit on neutrino fluence at the Earth
$\mathit{\Phi}<1.1\times10^{6}$ $\mathrm{cm^{-2}}$ at the $90\%$ confidence
level for the largest solar flare. The resulting fluence limits allow us to
constrain some of the theoretical models for solar-flare neutrino emission.
- Uncovering the neutrino mass ordering with the next galactic
core-collapse supernova neutrino burst using water Cherenkov detectors
2210.11676 [abs] [pdf]
[abstract]
by César Jesús-Valls.
A major challenge of particle physics is determining the neutrino mass
ordering (MO). Due to matter effects, the flavor content of the neutrino flux
from a Core-Collapse Supernova (CCSN) depends on the true neutrino MO resulting
in markedly different energy and angle distributions for the measured lepton in
water Cherenkov neutrino detectors. In this article, those distributions are
compared for eight different CCSN models and used to study how their
differences affect the determination of the neutrino mass ordering. In all
cases, the inferred neutrino mass ordering is found to be either correct or
inconclusive, with no significant false positives. However, the substantial
variation observed among model predictions emphasizes the criticality of
ongoing research in CCSN modeling.
- A lab scale experiment for keV sterile neutrino search
2210.11108 [abs] [pdf]
[abstract]
by Y. C. Lee, [and 9 more]H. B. Kim, H. L. Kim, S. K. Kim, Y. H. Kim, D. H. Kwon, H. S. Lim, H. S. Park, K. R. Woo, and Y. S. Yoon [hide authors].
We developed a simple small-scale experiment to measure the beta decay
spectrum of $^{3}$H. The aim of this research is to investigate the presence of
sterile neutrinos in the keV region. Tritium nuclei were embedded in a
1$\times$1$\times$1 cm$^3$ LiF crystal from the $^6$Li(n,$\alpha$)$^3$H
reaction. The energy of the beta electrons absorbed in the LiF crystal was
measured with a magnetic microcalorimeter at 40 mK. We report a new method of
sample preparation, experiments, and analysis of $^3$H beta measurements. The
spectrum of a 10-hour measurement agrees well with the expected spectrum of
$^3$H beta decay. The analysis results indicate that this method can be used to
search for keV-scale sterile neutrinos.
- First constraints on light sterile neutrino oscillations from combined
appearance and disappearance searches with the MicroBooNE detector
2210.10216 [abs] [pdf]
[abstract]
by MicroBooNE collaboration, [and 186 more]P. Abratenko, D. Andrade Aldana, J. Anthony, L. Arellano, J. Asaadi, A. Ashkenazi, S. Balasubramanian, B. Baller, G. Barr, J. Barrow, V. Basque, L. Bathe-Peters, O. Benevides Rodrigues, S. Berkman, A. Bhanderi, M. Bhattacharya, M. Bishai, A. Blake, B. Bogart, T. Bolton, J. Y. Book, L. Camilleri, D. Caratelli, I. Caro Terrazas, F. Cavanna, G. Cerati, Y. Chen, J. M. Conrad, M. Convery, L. Cooper-Troendle, J. I. Crespo-Anadon, M. Del Tutto, S. R. Dennis, P. Detje, A. Devitt, R. Diurba, R. Dorrill, K. Duffy, S. Dytman, B. Eberly, A. Ereditato, J. J. Evans, R. Fine, O. G. Finnerud, B. T. Fleming, N. Foppiani, W. Foreman, D. Franco, A. P. Furmanski, D. Garcia-Gamez, S. Gardiner, G. Ge, S. Gollapinni, O. Goodwin, E. Gramellini, P. Green, H. Greenlee, W. Gu, R. Guenette, P. Guzowski, L. Hagaman, O. Hen, R. Hicks, C. Hilgenberg, G. A. Horton-Smith, B. Irwin, R. Itay, C. James, X. Ji, L. Jiang, J. H. Jo, R. A. Johnson, Y. J. Jwa, D. Kalra, N. Kamp, G. Karagiorgi, W. Ketchum, M. Kirby, T. Kobilarcik, I. Kreslo, M. B. Leibovitch, I. Lepetic, J. -Y. Li, K. Li, Y. Li, K. Lin, B. R. Littlejohn, W. C. Louis, X. Luo, K. Manivannan, C. Mariani, D. Marsden, J. Marshall, N. Martinez, D. A. Martinez Caicedo, K. Mason, A. Mastbaum, N. McConkey, V. Meddage, K. Miller, J. Mills, K. Mistry, T. Mohayai, A. Mogan, M. Mooney, A. F. Moor, C. D. Moore, L. Mora Lepin, J. Mousseau, S. Mulleria Babu, D. Naples, A. Navrer-Agasson, N. Nayak, M. Nebot-Guinot, J. Nowak, M. Nunes, N. Oza, O. Palamara, N. Pallat, V. Paolone, A. Papadopoulou, V. Papavassiliou, H. Parkinson, S. F. Pate, N. Patel, Z. Pavlovic, E. Piasetzky, I. Ponce-Pinto, I. Pophale, S. Prince, X. Qian, J. L. Raaf, V. Radeka, M. Reggiani-Guzzo, L. Ren, L. Rochester, J. Rodriguez Rondon, M. Rosenberg, M. Ross-Lonergan, C. Rudolph von Rohr, G. Scanavini, D. W. Schmitz, A. Schukraft, W. Seligman, M. H. Shaevitz, R. Sharankova, J. Shi, A. Smith, E. L. Snider, M. Soderberg, S. Soldner-Rembold, J. Spitz, M. Stancari, J. St. John, T. Strauss, S. Sword-Fehlberg, A. M. Szelc, W. Tang, N. Taniuchi, K. Terao, C. Thorpe, D. Torbunov, D. Totani, M. Toups, Y. -T. Tsai, J. Tyler, M. A. Uchida, T. Usher, B. Viren, M. Weber, H. Wei, A. J. White, Z. Williams, S. Wolbers, T. Wongjirad, M. Wospakrik, K. Wresilo, N. Wright, W. Wu, E. Yandel, T. Yang, L. E. Yates, H. W. Yu, G. P. Zeller, J. Zennamo, and C. Zhang [hide authors].
We present a search for eV-scale sterile neutrino oscillations in the
MicroBooNE liquid argon detector, simultaneously considering all possible
appearance and disappearance effects within the $3+1$ active-to-sterile
neutrino oscillation framework. We analyze the neutrino candidate events for
the recent measurements of charged-current $\nu_e$ and $\nu_{\mu}$ interactions
in the MicroBooNE detector, using data corresponding to an exposure of
6.37$\times$10$^{20}$ protons on target from the Fermilab booster neutrino
beam. We observe no evidence of light sterile neutrino oscillations and derive
exclusion contours at the $95\%$ confidence level in the plane of the
mass-squared splitting $\Delta m^2_{41}$ and the sterile neutrino mixing angles
$\theta_{\mu e}$ and $\theta_{ee}$, excluding part of the parameter space
allowed by experimental anomalies. Cancellation of $\nu_e$ appearance and
$\nu_e$ disappearance effects due to the full $3+1$ treatment of the analysis
leads to a degeneracy when determining the oscillation parameters, which is
discussed in this paper and will be addressed by future analyses.
- Symmetry in neutrino oscillation in matter: New picture and the $ν$SM
-- non-unitarity interplay
2210.09453 [abs] [pdf]
[abstract]
by Hisakazu Minakata.
We update and summarize the present status of our understanding of the
reparametrization symmetry with $i \leftrightarrow j$ state exchange in
neutrino oscillation in matter. We introduce a systematic method called
``Symmetry Finder'' (SF) to uncover such symmetries, demonstrate its efficient
hunting capability, and examine their characteristic features. Apparently they
have a local nature: The 1-2 and 1-3 state exchange symmetries exist at around
the solar- and atmospheric-resonances, respectively, with the level-crossing
states exchanged. However, this view is not supported, to date, in the globally
valid Denton et al. (DMP) perturbation theory, which possesses the 1-2 exchange
symmetry but not the 1-3. It is probably due to lack of our understanding, and
we find a clue for a larger symmetry structure than that we know. In the latter
part of this article, we introduce non-unitarity, or unitarity violation (UV),
into the $\nu$SM neutrino paradigm, a low-energy description of beyond $\nu$SM
new physics at high (or low) scale. Based on the analyses of UV extended
versions of the atmospheric-resonance and the DMP perturbation theories, we
argue that the reparametrization symmetry has a diagnostics capability for the
theory with the $\nu$SM and UV sectors. A speculation is given on the
topological nature of the identity which determines the transformation property
of the UV $\alpha$ parameters.
- Expected geoneutrino signal at JUNO using local integrated 3-D refined
crustal model
2210.09165 [abs] [pdf]
[abstract]
by Ran Han, [and 13 more]ZhiWei Li, Ruohan Gao, Yao Sun, Ya Xu, Yaping Cheng, Guangzheng Jiang, Jie Pang, Fengcheng Liu, Andong Wang, Yufei Xi, Liangjian Wen, Jun Cao, and Yu-Feng Li [hide authors].
Geoneutrinos are a unique tool that brings to the surface information about
our planet, in particular, its radiogenic power, insights formation and
chemical composition. To date, only the KamLAND and Borexino experiments
observed geoneutrino, with the former characterized by low concentration of
heat-producing elements in the Earth in contrast to the latter that sets tight
upper limits on the power of a georeactor hypothesized. With respect to the
results yielded therefrom, a small discrepancy has been identified. On this
account, next generation experiments like JUNO are needed if it is to provide
definitive results with respect to the Earth's radiogenic power, and to fully
exploit geoneutrinos to better understand deep Earth.
An accurate a priori prediction of the crustal contribution plays an
important role in enabling the translation of a particle physics measurement
into geo-scientific questions. The existing GIGJ model of JUNO only focused on
constructing a geophysical model of the local crust, without local geochemical
data. Another existing JULOC includes both data, but only able to be achieved
for the top layer of the upper crust, not in deep vertical. This paper reports
on the development of JUNO's first 3-D integrated model, JULOC-I, which
combines seismic, gravity, rock sample and thermal flow data with new building
method, solved the problem in vertical depth.
JULOC-I results show higher than expected geoneutrino signals are mainly
attributable to higher U and Th in southern China than that found elsewhere on
Earth. Moreover, the high level of accuracy of the JULOC-I model, complemented
by 10 years of experimental data, indicates that JUNO has an opportunity to
test different mantle models. Predictions by JULOC-I can be tested after JUNO
goes online and higher accuracy local crustal model continue to play an
important role to improve mantle measurements precision.
- Effect of Matter Density in T2HK and DUNE
2210.09103 [abs] [pdf]
[abstract]
by Monojit Ghosh and Osamu Yasuda.
CP phase determination for the near future long baseline experiments, T2HK
and DUNE, will require precise measurements of the oscillation probabilities.
However, the uncertainty in the Earth's density must be considered in
determining these oscillation probabilities. Therefore, in this study, we
update the individual sensitivities of these experiments for determining the
current unknowns in the standard three flavor scenario considering the latest
configuration and also the complementarity between them while considering the
uncertainty in the density. Our study showed that this uncertainty has a
non-negligible impact on the precision of the CP phase determination
particularly for DUNE.
- Model Independent Approach of the JUNO $^8$B Solar Neutrino Program
2210.08437 [abs] [pdf]
[abstract]
by JUNO Collaboration, [and 603 more]Jie Zhao, Baobiao Yue, Haoqi Lu, Yufeng Li, Jiajie Ling, Zeyuan Yu, Angel Abusleme, Thomas Adam, Shakeel Ahmad, Rizwan Ahmed, Sebastiano Aiello, Muhammad Akram, Abid Aleem, Tsagkarakis Alexandros, Fengpeng An, Qi An, Giuseppe Andronico, Nikolay Anfimov, Vito Antonelli, Tatiana Antoshkina, Burin Asavapibhop, João Pedro Athayde Marcondes de André, Didier Auguste, Weidong Bai, Nikita Balashov, Wander Baldini, Andrea Barresi, Davide Basilico, Eric Baussan, Marco Bellato, Antonio Bergnoli, Thilo Birkenfeld, Sylvie Blin, David Blum, Simon Blyth, Anastasia Bolshakova, Mathieu Bongrand, Clément Bordereau, Dominique Breton, Augusto Brigatti, Riccardo Brugnera, Riccardo Bruno, Antonio Budano, Jose Busto, Ilya Butorov, Anatael Cabrera, Barbara Caccianiga, Hao Cai, Xiao Cai, Yanke Cai, Zhiyan Cai, Riccardo Callegari, Antonio Cammi, Agustin Campeny, Chuanya Cao, Guofu Cao, Jun Cao, Rossella Caruso, Cédric Cerna, Chi Chan, Jinfan Chang, Yun Chang, Guoming Chen, Pingping Chen, Po-An Chen, Shaomin Chen, Xurong Chen, Yixue Chen, Yu Chen, Zhiyuan Chen, Zikang Chen, Jie Cheng, Yaping Cheng, Alexander Chepurnov, Alexey Chetverikov, Davide Chiesa, Pietro Chimenti, Artem Chukanov, Gérard Claverie, Catia Clementi, Barbara Clerbaux, Marta Colomer Molla, Selma Conforti Di Lorenzo, Daniele Corti, Flavio Dal Corso, Olivia Dalager, Christophe De La Taille, Zhi Deng, Ziyan Deng, Wilfried Depnering, Marco Diaz, Xuefeng Ding, Yayun Ding, Bayu Dirgantara, Sergey Dmitrievsky, Tadeas Dohnal, Dmitry Dolzhikov, Georgy Donchenko, Jianmeng Dong, Evgeny Doroshkevich, Marcos Dracos, Frédéric Druillole, Ran Du, Shuxian Du, Stefano Dusini, Martin Dvorak, Timo Enqvist, Heike Enzmann, Andrea Fabbri, Donghua Fan, Lei Fan, Jian Fang, Wenxing Fang, Marco Fargetta, Dmitry Fedoseev, Zhengyong Fei, Li-Cheng Feng, Qichun Feng, Richard Ford, Amélie Fournier, Haonan Gan, Feng Gao, Alberto Garfagnini, Arsenii Gavrikov, Marco Giammarchi, Nunzio Giudice, Maxim Gonchar, Guanghua Gong, Hui Gong, Yuri Gornushkin, Alexandre Göttel, Marco Grassi, Maxim Gromov, Vasily Gromov, Minghao Gu, Xiaofei Gu, Yu Gu, Mengyun Guan, Yuduo Guan, Nunzio Guardone, Cong Guo, Jingyuan Guo, Wanlei Guo, Xinheng Guo, Yuhang Guo, Paul Hackspacher, Caren Hagner, Ran Han, Yang Han, Miao He, Wei He, Tobias Heinz, Patrick Hellmuth, Yuekun Heng, Rafael Herrera, YuenKeung Hor, Shaojing Hou, Yee Hsiung, Bei-Zhen Hu, Hang Hu, Jianrun Hu, Jun Hu, Shouyang Hu, Tao Hu, Yuxiang Hu, Zhuojun Hu, Guihong Huang, Hanxiong Huang, Kaixuan Huang, Wenhao Huang, Xin Huang, Xingtao Huang, Yongbo Huang, Jiaqi Hui, Lei Huo, Wenju Huo, Cédric Huss, Safeer Hussain, Ara Ioannisian, Roberto Isocrate, Beatrice Jelmini, Ignacio Jeria, Xiaolu Ji, Huihui Jia, Junji Jia, Siyu Jian, Di Jiang, Wei Jiang, Xiaoshan Jiang, Xiaoping Jing, Cécile Jollet, Leonidas Kalousis, Philipp Kampmann, Li Kang, Rebin Karaparambil, Narine Kazarian, Amina Khatun, Khanchai Khosonthongkee, Denis Korablev, Konstantin Kouzakov, Alexey Krasnoperov, Nikolay Kutovskiy, Pasi Kuusiniemi, Tobias Lachenmaier, Cecilia Landini, Sébastien Leblanc, Victor Lebrin, Frederic Lefevre, Ruiting Lei, Rupert Leitner, Jason Leung, Daozheng Li, Demin Li, Fei Li, Fule Li, Gaosong Li, Huiling Li, Mengzhao Li, Min Li, Nan Li, Nan Li, Qingjiang Li, Ruhui Li, Rui Li, Shanfeng Li, Tao Li, Teng Li, Weidong Li, Weiguo Li, Xiaomei Li, Xiaonan Li, Xinglong Li, Yi Li, Yichen Li, Zepeng Li, Zhaohan Li, Zhibing Li, Ziyuan Li, Zonghai Li, Hao Liang, Hao Liang, Jiajun Liao, Ayut Limphirat, Guey-Lin Lin, Shengxin Lin, Tao Lin, Ivano Lippi, Fang Liu, Haidong Liu, Haotian Liu, Hongbang Liu, Hongjuan Liu, Hongtao Liu, Hui Liu, Jianglai Liu, Jinchang Liu, Min Liu, Qian Liu, Qin Liu, Runxuan Liu, Shubin Liu, Shulin Liu, Xiaowei Liu, Xiwen Liu, Yan Liu, Yunzhe Liu, Alexey Lokhov, Paolo Lombardi, Claudio Lombardo, Kai Loo, Chuan Lu, Jingbin Lu, Junguang Lu, Shuxiang Lu, Bayarto Lubsandorzhiev, Sultim Lubsandorzhiev, Livia Ludhova, Arslan Lukanov, Daibin Luo, Fengjiao Luo, Guang Luo, Shu Luo, Wuming Luo, Xiaojie Luo, Vladimir Lyashuk, Bangzheng Ma, Bing Ma, Qiumei Ma, Si Ma, Xiaoyan Ma, Xubo Ma, Jihane Maalmi, Jingyu Mai, Yury Malyshkin, Roberto Carlos Mandujano, Fabio Mantovani, Francesco Manzali, Xin Mao, Yajun Mao, Stefano M. Mari, Filippo Marini, Cristina Martellini, Gisele Martin-Chassard, Agnese Martini, Matthias Mayer, Davit Mayilyan, Ints Mednieks, Yue Meng, Anselmo Meregaglia, Emanuela Meroni, David Meyhöfer, Mauro Mezzetto, Jonathan Miller, Lino Miramonti, Paolo Montini, Michele Montuschi, Axel Müller, Massimiliano Nastasi, Dmitry V. Naumov, Elena Naumova, Diana Navas-Nicolas, Igor Nemchenok, Minh Thuan Nguyen Thi, Alexey Nikolaev, Feipeng Ning, Zhe Ning, Hiroshi Nunokawa, Lothar Oberauer, Juan Pedro Ochoa-Ricoux, Alexander Olshevskiy, Domizia Orestano, Fausto Ortica, Rainer Othegraven, Alessandro Paoloni, Sergio Parmeggiano, Yatian Pei, Nicomede Pelliccia, Anguo Peng, Haiping Peng, Yu Peng, Zhaoyuan Peng, Frédéric Perrot, Pierre-Alexandre Petitjean, Fabrizio Petrucci, Oliver Pilarczyk, Luis Felipe Piñeres Rico, Artyom Popov, Pascal Poussot, Ezio Previtali, Fazhi Qi, Ming Qi, Sen Qian, Xiaohui Qian, Zhen Qian, Hao Qiao, Zhonghua Qin, Shoukang Qiu, Gioacchino Ranucci, Neill Raper, Alessandra Re, Henning Rebber, Abdel Rebii, Mariia Redchuk, Mariia Redchuk, Bin Ren, Jie Ren, Barbara Ricci, Mariam Rifai, Mathieu Roche, Narongkiat Rodphai, Aldo Romani, Bedřich Roskovec, Xichao Ruan, Arseniy Rybnikov, Andrey Sadovsky, Paolo Saggese, Simone Sanfilippo, Anut Sangka, Utane Sawangwit, Julia Sawatzki, Michaela Schever, Cédric Schwab, Konstantin Schweizer, Alexandr Selyunin, Andrea Serafini, Giulio Settanta, Mariangela Settimo, Zhuang Shao, Vladislav Sharov, Arina Shaydurova, Jingyan Shi, Yanan Shi, Vitaly Shutov, Andrey Sidorenkov, Fedor Šimkovic, Chiara Sirignano, Jaruchit Siripak, Monica Sisti, Maciej Slupecki, Mikhail Smirnov, Oleg Smirnov, Thiago Sogo-Bezerra, Sergey Sokolov, Julanan Songwadhana, Boonrucksar Soonthornthum, Albert Sotnikov, Ondřej Šrámek, Warintorn Sreethawong, Achim Stahl, Luca Stanco, Konstantin Stankevich, Dušan Štefánik, Hans Steiger, Jochen Steinmann, Tobias Sterr, Matthias Raphael Stock, Virginia Strati, Alexander Studenikin, Jun Su, Shifeng Sun, Xilei Sun, Yongjie Sun, Yongzhao Sun, Zhengyang Sun, Narumon Suwonjandee, Michal Szelezniak, Jian Tang, Qiang Tang, Quan Tang, Xiao Tang, Alexander Tietzsch, Igor Tkachev, Tomas Tmej, Marco Danilo Claudio Torri, Konstantin Treskov, Andrea Triossi, Giancarlo Troni, Wladyslaw Trzaska, Cristina Tuve, Nikita Ushakov, Vadim Vedin, Giuseppe Verde, Maxim Vialkov, Benoit Viaud, Cornelius Moritz Vollbrecht, Cristina Volpe, Katharina von Sturm, Vit Vorobel, Dmitriy Voronin, Lucia Votano, Pablo Walker, Caishen Wang, Chung-Hsiang Wang, En Wang, Guoli Wang, Jian Wang, Jun Wang, Lu Wang, Meifen Wang, Meng Wang, Meng Wang, Ruiguang Wang, Siguang Wang, Wei Wang, Wei Wang, Wenshuai Wang, Xi Wang, Xiangyue Wang, Yangfu Wang, Yaoguang Wang, Yi Wang, Yi Wang, Yifang Wang, Yuanqing Wang, Yuman Wang, Zhe Wang, Zheng Wang, Zhimin Wang, Zongyi Wang, Apimook Watcharangkool, Wei Wei, Wei Wei, Wenlu Wei, Yadong Wei, Kaile Wen, Liangjian Wen, Christopher Wiebusch, Steven Chan-Fai Wong, Bjoern Wonsak, Diru Wu, Qun Wu, Zhi Wu, Michael Wurm, Jacques Wurtz, Christian Wysotzki, Yufei Xi, Dongmei Xia, Xiang Xiao, Xiaochuan Xie, Yuguang Xie, Zhangquan Xie, Zhao Xin, Zhizhong Xing, Benda Xu, Cheng Xu, Donglian Xu, Fanrong Xu, Hangkun Xu, Jilei Xu, Jing Xu, Meihang Xu, Yin Xu, Yu Xu, Baojun Yan, Taylor Yan, Wenqi Yan, Xiongbo Yan, Yupeng Yan, Changgen Yang, Chengfeng Yang, Huan Yang, Jie Yang, Lei Yang, Xiaoyu Yang, Yifan Yang, Yifan Yang, Haifeng Yao, Jiaxuan Ye, Mei Ye, Ziping Ye, Frédéric Yermia, Na Yin, Zhengyun You, Boxiang Yu, Chiye Yu, Chunxu Yu, Hongzhao Yu, Miao Yu, Xianghui Yu, Zezhong Yu, Cenxi Yuan, Chengzhuo Yuan, Ying Yuan, Zhenxiong Yuan, Noman Zafar, Vitalii Zavadskyi, Shan Zeng, Tingxuan Zeng, Yuda Zeng, Liang Zhan, Aiqiang Zhang, Bin Zhang, Binting Zhang, Feiyang Zhang, Guoqing Zhang, Honghao Zhang, Jialiang Zhang, Jiawen Zhang, Jie Zhang, Jin Zhang, Jingbo Zhang, Jinnan Zhang, Mohan Zhang, Peng Zhang, Qingmin Zhang, Shiqi Zhang, Shu Zhang, Tao Zhang, Xiaomei Zhang, Xin Zhang, Xuantong Zhang, Xueyao Zhang, Yinhong Zhang, Yiyu Zhang, Yongpeng Zhang, Yu Zhang, Yuanyuan Zhang, Yumei Zhang, Zhenyu Zhang, Zhijian Zhang, Fengyi Zhao, Rong Zhao, Runze Zhao, Shujun Zhao, Dongqin Zheng, Hua Zheng, Yangheng Zheng, Weirong Zhong, Jing Zhou, Li Zhou, Nan Zhou, Shun Zhou, Tong Zhou, Xiang Zhou, Jiang Zhu, Jingsen Zhu, Kangfu Zhu, Kejun Zhu, Zhihang Zhu, Bo Zhuang, Honglin Zhuang, Liang Zong, and Jiaheng Zou [hide authors].
The physics potential of detecting $^8$B solar neutrinos is exploited at the
Jiangmen Underground Neutrino Observatory (JUNO), in a model independent manner
by using three distinct channels of the charged-current (CC), neutral-current
(NC) and elastic scattering (ES) interactions. Due to the largest-ever mass of
$^{13}$C nuclei in the liquid-scintillator detectors and the potential low
background level, $^8$B solar neutrinos would be observable in the CC and NC
interactions on $^{13}$C for the first time. By virtue of optimized event
selections and muon veto strategies, backgrounds from the accidental
coincidence, muon-induced isotopes, and external backgrounds can be greatly
suppressed. Excellent signal-to-background ratios can be achieved in the CC, NC
and ES channels to guarantee the $^8$B solar neutrino observation. From the
sensitivity studies performed in this work, we show that one can reach the
precision levels of 5%, 8% and 20% for the $^8$B neutrino flux,
$\sin^2\theta_{12}$, and $\Delta m^2_{21}$, respectively, using ten years of
JUNO data. It would be unique and helpful to probe the details of both solar
physics and neutrino physics. In addition, when combined with SNO, the
world-best precision of 3% is expected for the $^8$B neutrino flux measurement.
- Interpreting Reactor Antineutrino Anomalies with STEREO data
2210.07664 [abs] [pdf]
[abstract]
by H. Almazán, [and 23 more]L. Bernard, A. Blanchet, A. Bonhomme, C. Buck, A. Chalil, P. del Amo Sanchez, I. El Atmani, L. Labit, J. Lamblin A. Letourneau D. Lhuillier, M. Licciardi, M. Lindner, T. Materna, H. Pessard, J. -S. Réal, J. -S. Ricol, C. Roca, R. Rogly, T. Salagnac, V. Savu, S. Schoppmann, T. Soldner, A. Stutz, and M. Vialat [hide authors].
Anomalies in past neutrino measurements have led to the discovery that these
particles have non-zero mass and oscillate between their three flavors when
they propagate. In the 2010's, similar anomalies observed in the antineutrino
spectra emitted by nuclear reactors have triggered the hypothesis of the
existence of a supplementary neutrino state that would be sterile i.e. not
interacting via the weak interaction. The STEREO experiment was designed to
study this scientific case that would potentially extend the Standard Model of
Particle Physics. Here we present a complete study based on our full set of
data with significantly improved sensitivity. Installed at the ILL (Institut
Laue Langevin) research reactor, STEREO has accurately measured the
antineutrino energy spectrum associated to the fission of 235U. This
measurement confirms the anomalies whereas, thanks to the segmentation of the
STEREO detector and its very short mean distance to the core (10~m), the same
data reject the hypothesis of a light sterile neutrino. Such a direct
measurement of the antineutrino energy spectrum suggests instead that biases in
the nuclear experimental data used for the predictions are at the origin of the
anomalies. Our result supports the neutrino content of the Standard Model and
establishes a new reference for the 235U antineutrino energy spectrum. We
anticipate that this result will allow to progress towards finer tests of the
fundamental properties of neutrinos but also to benchmark models and nuclear
data of interest for reactor physics and for observations of astrophysical or
geo-neutrinos.
- Impact of the finite life-time of UHECR sources
2210.07090 [abs] [pdf]
[abstract]
by Björn Eichmann and Michael Kachelrieß.
The observational data on ultrahigh energy cosmic rays (UHECR), in particular
their mass composition, show strong indications for extremely hard spectra of
individual mass groups of CR nuclei at Earth. In this work, we show that such
hard spectra can be the result of the finite life-time of UHECR sources, if a
few individual sources dominate the UHECR flux at the highest energies. In this
case, time delays induced by deflections in the turbulent extragalactic
magnetic field as well as from the diffusive or advective escape from the
source environment can suppress low-energy CRs, leading to a steepening of the
observed spectrum. Considering radio galaxies as the main source of UHECRs, we
discuss the necessary conditions that few individual sources dominate over the
total contribution from the bulk of sources that have been active in the past.
We provide two proof-of-principle scenarios showing that for a turbulent
extragalactic magnetic field with a strength $B$ and a coherence length $l_{\rm
coh}$, the life-time of a source at a distance $d_{\rm src}$ should satisfy
${t_{\rm act} \sim \left( B/1\,\text{nG} \right)^2\,\left( d_{\rm
src}/10\,\text{Mpc} \right)^2\,\left( l_{\rm coh}/1\,\text{Mpc}
\right)\,\text{Myr}}$ to obtain the necessary hardening of the CR spectrum at
Earth.
- Evidence of a signature of planet formation processes from solar
neutrino fluxes
2210.06900 [abs] [pdf]
[abstract]
by Masanobu Kunitomo, Tristan Guillot, and Gaël Buldgen.
Solar evolutionary models are thus far unable to reproduce spectroscopic,
helioseismic, and neutrino constraints consistently, resulting in the so-called
solar modeling problem. In parallel, planet formation models predict that the
evolving composition of the protosolar disk and, thus, of the gas accreted by
the proto-Sun must have been variable. We show that solar evolutionary models
that include a realistic planet formation scenario lead to an increased core
metallicity of up to 5%, implying that accurate neutrino flux measurements are
sensitive to the initial stages of the formation of the Solar System. Models
with homogeneous accretion match neutrino constraints to no better than
2.7$\sigma$. In contrast, accretion with a variable composition due to planet
formation processes, leading to metal-poor accretion of the last $\sim$4% of
the young Sun's total mass, yields solar models within 1.3$\sigma$ of all
neutrino constraints. We thus demonstrate that in addition to increased
opacities at the base of the convective envelope, the formation history of the
Solar System constitutes a key element in resolving the current crisis of solar
models.
- Astrophysical searches of ultralight particles
2210.06837 [abs] [pdf]
[abstract]
by Tanmay Kumar Poddar.
The Standard Model of particle physics is a $SU(3)_c\times SU(2)_L\times
U(1)_Y$ gauge theory that can explain the strong, weak, and electromagnetic
interactions between the particles. The gravitational interaction is described
by Einstein's General Relativity theory which is a classical theory of gravity.
These theories can explain all the four fundamental forces of nature with great
level of accuracy. However, there are several theoretical and experimental
motivations of studying physics beyond the Standard Model of particle physics
and Einstein's General Relativity theory. Probing these new physics scenarios
with ultralight particles has its own importance as they can be a promising
candidates for dark matter that can evade the constraints from dark matter
direct detection experiments and solve the small scale structure problems of
the universe. In this paper, we have considered axions and gauge bosons as
light particles and their possible searches through astrophysical observations.
In particular, we obtain constraints on ultralight axions from orbital period
loss of compact binary systems, gravitational light bending, and Shapiro time
delay. We also derive constraints on ultralight gauge bosons from indirect
evidence of gravitational waves, and perihelion precession of planets. Such
type of observations can also constrain several particle physics models and are
discussed.
- Lorentz invariance violation induced threshold anomaly versus very-high
energy cosmic photon emission from GRB 221009A
2210.06338 [abs] [pdf]
[abstract]
by Hao Li and Bo-Qiang Ma.
It has been reported that the Large High Altitude Air Shower Observatory
(LHAASO) observed very high energy photons from GRB 221009A, with the highest
energy reaching 18~TeV. We find that observation of such high energy photons is
quite nontrivial since extragalactic background light could absorb these
photons severely and the flux is too weak to be observed. Therefore we discuss
a potential mechanism for us to observe these photons, and suggest that Lorentz
invariance violation induced threshold anomaly of the process \(\gamma\gamma\to
e^-e^+\) provides a candidate to explain this phenomenon.
- Constraints on populations of neutrino sources from searches in the
directions of IceCube neutrino alerts
2210.04930 [abs] [pdf]
[abstract]
by R. Abbasi, [and 383 more]M. Ackermann, J. Adams, N. Aggarwal, J. A. Aguilar, M. Ahlers, J. M. Alameddine, A. A. Alves Jr., N. M. Amin, K. Andeen, T. Anderson, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, V. Basu, R. Bay, J. J. Beatty, K. -H. Becker, J. Becker Tjus, J. Beise, C. Bellenghi, S. Benda, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, G. Binder, D. Bindig, E. Blaufuss, S. Blot, F. Bontempo, J. Y. Book, J. Borowka, C. Boscolo Meneguolo, S. Böser, O. Botner, J. Böttcher, E. Bourbeau, J. Braun, B. Brinson, J. Brostean-Kaiser, R. T. Burley, R. S. Busse, M. A. Campana, E. G. Carnie-Bronca, C. Chen, Z. Chen, D. Chirkin, K. Choi, B. A. Clark, L. Classen, A. Coleman, G. H. Collin, A. Connolly, J. M. Conrad, P. Coppin, P. Correa, S. Countryman, D. F. Cowen, R. Cross, C. Dappen, P. Dave, C. De Clercq, J. J. DeLaunay, D. Delgado López, H. Dembinski, K. Deoskar, A. Desai, P. Desiati, K. D. de Vries, G. de Wasseige, T. DeYoung, A. Diaz, J. C. Díaz-Vélez, M. Dittmer, H. Dujmovic, M. A. DuVernois, T. Ehrhardt, P. Eller, R. Engel, H. Erpenbeck, J. Evans, P. A. Evenson, K. L. Fan, A. R. Fazely, A. Fedynitch, N. Feigl, S. Fiedlschuster, A. T. Fienberg, C. Finley, L. Fischer, D. Fox, A. Franckowiak, E. Friedman, A. Fritz, P. Fürst, T. K. Gaisser, J. Gallagher, E. Ganster, A. Garcia, S. Garrappa, L. Gerhardt, A. Ghadimi, C. Glaser, T. Glauch, T. Glüsenkamp, N. Goehlke, J. G. Gonzalez, S. Goswami, D. Grant, S. J. Gray, T. Grégoire, S. Griswold, C. Günther, P. Gutjahr, C. Haack, A. Hallgren, R. Halliday, L. Halve, F. Halzen, H. Hamdaoui, M. Ha Minh, K. Hanson, J. Hardin, A. A. Harnisch, P. Hatch, A. Haungs, K. Helbing, J. Hellrung, F. Henningsen, L. Heuermann, S. Hickford, A. Hidvegi, C. Hill, G. C. Hill, K. D. Hoffman, K. Hoshina, W. Hou, T. Huber, K. Hultqvist, M. Hünnefeld, R. Hussain, K. Hymon, S. In, N. Iovine, A. Ishihara, M. Jansson, G. S. Japaridze, M. Jeong, M. Jin, B. J. P. Jones, D. Kang, W. Kang, X. Kang, A. Kappes, D. Kappesser, L. Kardum, T. Karg, M. Karl, A. Karle, U. Katz, M. Kauer, J. L. Kelley, A. Kheirandish, K. Kin, J. Kiryluk, S. R. Klein, A. Kochocki, R. Koirala, H. Kolanoski, T. Kontrimas, L. Köpke, C. Kopper, D. J. Koskinen, P. Koundal, M. Kovacevich, M. Kowalski, T. Kozynets, E. Krupczak, E. Kun, N. Kurahashi, N. Lad, C. Lagunas Gualda, M. J. Larson, F. Lauber, J. P. Lazar, J. W. Lee, K. Leonard, A. Leszczyńska, M. Lincetto, Q. R. Liu, M. Liubarska, E. Lohfink, C. Love, C. J. Lozano Mariscal, L. Lu, F. Lucarelli, A. Ludwig, W. Luszczak, Y. Lyu, W. Y. Ma, J. Madsen, K. B. M. Mahn, Y. Makino, S. Mancina, W. Marie Sainte, I. C. Mariş, S. Marka, Z. Marka, M. Marsee, I. Martinez-Soler, R. Maruyama, T. McElroy, F. McNally, J. V. Mead, K. Meagher, S. Mechbal, A. Medina, M. Meier, S. Meighen-Berger, Y. Merckx, J. Micallef, D. Mockler, T. Montaruli, R. W. Moore, R. Morse, M. Moulai, T. Mukherjee, R. Naab, R. Nagai, U. Naumann, A. Nayerhoda, J. Necker, M. Neumann, H. Niederhausen, M. U. Nisa, A. Noell, S. C. Nowicki, A. Obertacke Pollmann, M. Oehler, B. Oeyen, A. Olivas, R. Orsoe, J. Osborn, E. O'Sullivan, H. Pandya, D. V. Pankova, N. Park, G. K. Parker, E. N. Paudel, L. Paul, C. Pérez de los Heros, L. Peters, J. Peterson, S. Philippen, S. Pieper, A. Pizzuto, M. Plum, Y. Popovych, A. Porcelli, M. Prado Rodriguez, B. Pries, R. Procter-Murphy, G. T. Przybylski, C. Raab, J. Rack-Helleis, M. Rameez, K. Rawlins, Z. Rechav, A. Rehman, P. Reichherzer, G. Renzi, E. Resconi, S. Reusch, W. Rhode, M. Richman, B. Riedel, E. J. Roberts, S. Robertson, S. Rodan, G. Roellinghoff, M. Rongen, C. Rott, T. Ruhe, L. Ruohan, D. Ryckbosch, D. Rysewyk Cantu, I. Safa, J. Saffer, D. Salazar-Gallegos, P. Sampathkumar, S. E. Sanchez Herrera, A. Sandrock, M. Santander, S. Sarkar, S. Sarkar, J. Savelberg, M. Schaufel, H. Schieler, S. Schindler, B. Schlueter, T. Schmidt, J. Schneider, F. G. Schröder, L. Schumacher, G. Schwefer, S. Sclafani, S. Seunarine, A. Sharma, S. Shefali, N. Shimizu, M. Silva, B. Skrzypek, B. Smithers, R. Snihur, J. Soedingrekso, A. Søgaard, D. Soldin, C. Spannfellner, G. M. Spiczak, C. Spiering, M. Stamatikos, T. Stanev, R. Stein, T. Stezelberger, T. Stürwald, T. Stuttard, G. W. Sullivan, I. Taboada, S. Ter-Antonyan, W. G. Thompson, J. Thwaites, S. Tilav, K. Tollefson, C. Tönnis, S. Toscano, D. Tosi, A. Trettin, C. F. Tung, R. Turcotte, J. P. Twagirayezu, B. Ty, M. A. Unland Elorrieta, K. Upshaw, N. Valtonen-Mattila, J. Vandenbroucke, N. van Eijndhoven, D. Vannerom, J. van Santen, J. Vara, J. Veitch-Michaelis, S. Verpoest, D. Veske, C. Walck, W. Wang, T. B. Watson, C. Weaver, P. Weigel, A. Weindl, J. Weldert, C. Wendt, J. Werthebach, M. Weyrauch, N. Whitehorn, C. H. Wiebusch, N. Willey, D. R. Williams, M. Wolf, G. Wrede, J. Wulff, X. W. Xu, J. P. Yanez, E. Yildizci, S. Yoshida, S. Yu, T. Yuan, Z. Zhang, and P. Zhelnin [hide authors].
Beginning in 2016, the IceCube Neutrino Observatory has sent out alerts in
real time containing the information of high-energy ($E \gtrsim 100$~TeV)
neutrino candidate events with moderate-to-high ($\gtrsim 30$\%) probability of
astrophysical origin. In this work, we use a recent catalog of such alert
events, which, in addition to events announced in real-time, includes events
that were identified retroactively, and covers the time period of 2011-2020. We
also search for additional, lower-energy, neutrinos from the arrival directions
of these IceCube alerts. We show how performing such an analysis can constrain
the contribution of rare populations of cosmic neutrino sources to the diffuse
astrophysical neutrino flux. After searching for neutrino emission coincident
with these alert events on various timescales, we find no significant evidence
of either minute-scale or day-scale transient neutrino emission or of steady
neutrino emission in the direction of these alert events. This study also shows
how numerous a population of neutrino sources has to be to account for the
complete astrophysical neutrino flux. Assuming sources have the same
luminosity, an $E^{-2.5}$ neutrino spectrum and number densities that follow
star-formation rates, the population of sources has to be more numerous than
$7\times 10^{-9}~\textrm{Mpc}^{-3}$. This number changes to $3\times
10^{-7}~\textrm{Mpc}^{-3}$ if number densities instead have no cosmic
evolution.
- Directional Neutrino Searches for Galactic Center Dark Matter at Large
Underground LArTPCs
2210.04920 [abs] [pdf]
[abstract]
by Matthew R. Buckley, Andrew Mastbaum, and Gopolang Mohlabeng.
We investigate the sensitivity of a large, underground LArTPC-based neutrino
detector to dark matter in the Galactic Center annihilating into neutrinos.
Such a detector could have the ability to resolve the direction of the electron
in a neutrino scattering event, and thus to infer information about the source
direction for individual neutrino events. We consider the improvements on the
expected experimental sensitivity that this directional information would
provide. Even without directional information, we find a DUNE-like LArTPC
detector is capable of setting limits on dark matter annihilation to neutrinos
for dark matter masses above 30 MeV that are competitive with or exceed current
experimental reach. While currently-demonstrated angular resolution for
low-energy electrons is insufficient to allow any significant increase in
sensitivity, these techniques could benefit from improvements to algorithms and
the additional spatial information provided by novel 3D charge imaging
approaches. We consider the impact of such enhancements to the resolution for
electron directionality, and find that where electron-scattering events can be
distinguished from charged-current neutrino interactions, limits on dark matter
annihilation in the mass range where solar neutrino backgrounds dominate
($\lesssim 15$ MeV) can be significantly improved using directional
information, and would be competitive with existing limits using $40$
kton$\times$year of exposure.
- Monoenergetic Neutrinos from WIMP Annihilation in Jupiter
2210.04761 [abs] [pdf]
[abstract]
by George M. French and Marc Sher.
Weakly interacting massive particles (WIMPs) can be captured by the Sun and
annihilate in the core, which may result in production of kaons that can decay
at rest into monoenergetic 236 MeV neutrinos. Several studies of detection of
these neutrinos at DUNE have been carried out. It has been shown that if the
WIMP mass is below 4 GeV, then they will evaporate prior to annihilation,
suppressing the signal. Since Jupiter has a cooler core, WIMPs with masses in
the 1-4 GeV range will not evaporate and can thus annihilate into monoenergetic
neutrinos. We calculate the flux of these neutrinos near the surface of Jupiter
and find that it is comparable to the flux at DUNE for masses above 4 GeV and
substantially greater in the 1-4 GeV range. Of course, detecting these
neutrinos would require a neutrino detector near Jupiter. Obviously, it will be
many decades before such a detector can be built, but should direct detection
experiments find a WIMP with a mass in the 1-4 GeV range, it may be one of the
few ways to learn about the annihilation process. A liquid hydrogen time
projection chamber might be able to get precise directional information and
energy of these neutrinos (and hydrogen is plentiful in the vicinity of
Jupiter). We speculate that such a detector could be placed on the far side of
one of the tidally locked Amalthean moons; the moon itself would provide
substantial background shielding and the surface would allow easier deployment
of solar panels for power generation.
- The impact of neutrino-nucleus interaction modeling on new physics
searches
2210.03753 [abs] [pdf]
[abstract]
by Nina M. Coyle, Shirley Weishi Li, and Pedro A. N. Machado.
Accurate neutrino-nucleus interaction modeling is an essential requirement
for the success of the accelerator-based neutrino program. As no satisfactory
description of cross sections exists, experiments tune neutrino-nucleus
interactions to data to mitigate mis-modeling. In this work, we study how the
interplay between near detector tuning and cross section mis-modeling affects
new physics searches. We perform a realistic simulation of neutrino events and
closely follow NOvA's tuning, the first published of such procedures in a
neutrino experiment. We analyze two illustrative new physics scenarios, sterile
neutrinos and light neutrinophilic scalars, presenting the relevant
experimental signatures and the sensitivity regions with and without tuning.
While the tuning does not wash out sterile neutrino oscillation patterns, cross
section mis-modeling can bias the experimental sensitivity. In the case of
light neutrinophilic scalars, variations in cross section models completely
dominate the sensitivity regardless of any tuning. Our findings reveal the
critical need to improve our theoretical understanding of neutrino-nucleus
interactions, and to estimate the impact of tuning on new physics searches. We
urge neutrino experiments to follow NOvA's example and publish the details of
their tuning procedure, and to develop strategies to more robustly account for
cross section uncertainties, which will expand the scope of their physics
program.
- New Constraints on Dark Matter and Cosmic Neutrino Profiles through
Gravity
2210.03749 [abs] [pdf]
[abstract]
by Yu-Dai Tsai, [and 4 more]Joshua Eby, Jason Arakawa, Davide Farnocchia, and Marianna S. Safronova [hide authors].
We derive purely gravitational constraints on dark matter and cosmic neutrino
profiles in the solar system using asteroid (101955) Bennu. We focus on Bennu
because of its extensive tracking data and high-fidelity trajectory modeling
resulting from the OSIRIS-REx mission. We find that the local density of dark
matter is bound by $\rho_{\rm DM}\lesssim 3.3\times 10^{-15}\;\rm kg/m^3 \simeq
6\times10^6\,\bar{\rho}_{\rm DM}$, in the vicinity of $\sim 1.1$ au (where
$\bar{\rho}_{\rm DM}\simeq 0.3\;\rm GeV/cm^3$). We show that high-precision
tracking data of solar system objects can constrain cosmic neutrino
overdensities relative to the Standard Model prediction $\bar{n}_{\nu}$, at the
level of $\eta\equiv n_\nu/\bar{n}_{\nu}\lesssim 1.7 \times 10^{11}(0.1 \;{\rm
eV}/m_\nu)$ (Saturn), comparable to the existing bounds from KATRIN and other
previous laboratory experiments (with $m_\nu$ the neutrino mass). These local
bounds have interesting implications for existing and future direct-detection
experiments. Our constraints apply to all dark matter candidates but are
particularly meaningful for scenarios including solar halos, stellar basins,
and axion miniclusters, which predict or allow overdensities in the solar
system. Furthermore, introducing a DM-SM long-range fifth force with a strength
$\tilde{\alpha}_D$ times stronger than gravity, Bennu can set a constraint on
$\rho_{\rm DM}\lesssim \bar{\rho}_{\rm DM}\left(6 \times
10^6/\tilde{\alpha}_D\right)$. These constraints can be improved in the future
as the accuracy of tracking data improves, observational arcs increase, and
more missions visit asteroids.
- Decay of superluminal neutrinos in the collinear approximation
2210.02222 [abs] [pdf]
[abstract]
by J. M. Carmona, [and 3 more]J. L. Cortés, J. J. Relancio, and M. A. Reyes [hide authors].
The kinematics of the three body decay, with a modified energy-momentum
relation of the particles due to a violation of Lorentz invariance, is
presented in detail in the collinear approximation. The results are applied to
the decay of superluminal neutrinos producing an electron-positron or a
neutrino-antineutrino pair. Explicit expressions for the energy distributions,
required for a study of the cascade of neutrinos produced in the propagation of
superluminal neutrinos, are derived.
- High-energy neutrino-induced cascade from the direction of the flaring
radio blazar TXS 0506+056 observed by the Baikal Gigaton Volume Detector in
2021
2210.01650 [abs] [pdf]
[abstract]
by Baikal-GVD Collaboration, [and 10 more]A. K. Erkenov, N. A. Kosogorov, Y. A. Kovalev, Y. Y. Kovalev, A. V. Plavin, A. V. Popkov, A. B. Pushkarev, D. V. Semikoz, Y. V. Sotnikova, and S. V. Troitsky [hide authors].
The existence of high-energy astrophysical neutrinos has been unambiguously
demonstrated, but their sources remain elusive. IceCube reported an association
of a 290-TeV neutrino with a gamma-ray flare of TXS 0506+056, an active
galactic nucleus with a compact radio jet pointing to us. Later, radio blazars
were shown to be associated with IceCube neutrino events with high statistical
significance. These associations remained unconfirmed with the data of
independent experiments. Here we report on the detection of a rare neutrino
event with the estimated energy of 224 +- 75 TeV from the direction of TXS
0506+056 by the new Baikal-GVD neutrino telescope in April 2021 followed by a
radio flare observed by RATAN-600. This event is the highest-energy cascade
detected so far by Baikal-GVD from a direction below horizon. The result
supports previous suggestions that radio blazars in general, and TXS 0506+056
in particular, are the sources of high-energy neutrinos, and opens up the
cascade channel for the neutrino astronomy.
- Solar and supernova neutrino physics with future NaI(Tl) dark matter
search detectors
2210.01386 [abs] [pdf]
[abstract]
by Young Ju Ko and Hyun Su Lee.
We investigate the prospects for measuring the coherent elastic
neutrino-nucleus scattering of solar and supernova neutrinos in future NaI(Tl)
dark matter detection experiments. Considering the reduced background and
improved light yield of the recently developed NaI(Tl) crystals, more than
3$\sigma$ observation sensitivities of the supernova neutrino within the Milky
Way are demonstrated. In the case of the solar neutrino, approximately 3
observations are marginal with a 1 ton NaI(Tl) experiment assuming an order of
magnitude reduced background, five photoelectron thresholds, and 5-year data
exposure.
- Dark Matter decay to neutrinos
2210.01303 [abs] [pdf]
[abstract]
by Carlos A. Argüelles, [and 6 more]Diyaselis Delgado, Avi Friedlander, Ali Kheirandish, Ibrahim Safa, Aaron C. Vincent, and Henry White [hide authors].
It is possible that the strongest interactions between dark matter and the
Standard Model occur via the neutrino sector. Unlike gamma rays and charged
particles, neutrinos provide a unique avenue to probe for astrophysical sources
of dark matter, since they arrive unimpeded and undeflected from their sources.
Previously, we reported on annihilations of dark matter to neutrinos; here, we
review constraints on the decay of dark matter into neutrinos over a range of
dark matter masses from MeV to ZeV, compiling previously reported limits,
exploring new electroweak corrections and computing constraints where none have
been computed before. We examine the expected contributions to the neutrino
flux at current and upcoming neutrino experiments as well as photons from
electroweak emission expected at gamma-ray telescopes, leading to constraints
on the dark matter decay lifetime, which ranges from $\tau \sim
1.2\times10^{21}$ s at 10 MeV to $1.5\times10^{29}$s at 1 PeV.
September 2022
- How to Identify Different New Neutrino Oscillation Physics Scenarios at
DUNE
2210.00109 [abs] [pdf]
[abstract]
by Peter B. Denton, Alessio Giarnetti, and Davide Meloni.
Next generation neutrino oscillation experiments are expected to measure the
remaining oscillation parameters with very good precision. They will have
unprecedented capabilities to search for new physics that modify oscillations.
DUNE, with its broad band beam, good particle identification, and relatively
high energies will provide an excellent environment to search for new physics.
If deviations from the standard three-flavor oscillation picture are seen
however, it is crucial to know which new physics scenario is found so that it
can be verified elsewhere and theoretically understood. We investigate several
benchmark new physics scenarios by looking at existing long-baseline
accelerator neutrino data from NOvA and T2K and determine at what sensitivity
DUNE can differentiate among them. We consider sterile neutrinos and both
vector and scalar non-standard neutrino interactions, all with new complex
phases, the latter of which could conceivably provide absolute neutrino mass
scale information. We find that, in many interesting cases, DUNE will have good
model discrimination. We also perform a new fit to NOvA and T2K data with
scalar NSI.
- Neutrino propagation in the Earth and emerging charged leptons with
$\texttt{nuPyProp}$
2209.15581 [abs] [pdf]
[abstract]
by Diksha Garg, [and 24 more]Sameer Patel, Mary Hall Reno, Alexander Reustle, Yosui Akaike, Luis A. Anchordoqui, Douglas R. Bergman, Isaac Buckland, Austin L. Cummings, Johannes Eser, Fred Garcia, Claire Guépin, Tobias Heibges, Andrew Ludwig, John F. Krizmanic, Simon Mackovjak, Eric Mayotte, Sonja Mayotte, Angela V. Olinto, Thomas C. Paul, Andrés Romero-Wolf, Frédéric Sarazin, Tonia M. Venters, Lawrence Wiencke, and Stephanie Wissel [hide authors].
Ultra-high-energy neutrinos serve as messengers of some of the highest energy
astrophysical environments. Given that neutrinos are neutral and only interact
via weak interactions, neutrinos can emerge from sources, traverse astronomical
distances, and point back to their origins. Their weak interactions require
large target volumes for neutrino detection. Using the Earth as a neutrino
converter, terrestrial, sub-orbital, and satellite-based instruments are able
to detect signals of neutrino-induced extensive air showers. In this paper, we
describe the software code $\texttt{nuPyProp}$ that simulates tau neutrino and
muon neutrino interactions in the Earth and predicts the spectrum of the
$\tau$-lepton and muons that emerge. The $\texttt{nuPyProp}$ outputs are lookup
tables of charged lepton exit probabilities and energies that can be used
directly or as inputs to the $\texttt{nuSpaceSim}$ code designed to simulate
optical and radio signals from extensive air showers induced by the emerging
charged leptons. We describe the inputs to the code, demonstrate its
flexibility and show selected results for $\tau$-lepton and muon exit
probabilities and energy distributions. The $\texttt{nuPyProp}$ code is open
source, available on Github.
- Solar neutrino physics
2209.14832 [abs] [pdf]
[abstract]
by Xun-Jie Xu, Zhe Wang, and Shaomin Chen.
As a free, intensive, rarely interactive and well directional messenger,
solar neutrinos have been driving both solar physics and neutrino physics
developments for more than half a century. Since more extensive and advanced
neutrino experiments are under construction, being planned or proposed, we are
striving toward an era of precise and comprehensive measurement of solar
neutrinos in the next decades. In this article, we review recent theoretical
and experimental progress achieved in solar neutrino physics. We present not
only an introduction to neutrinos from the standard solar model and the
standard flavor evolution, but also a compilation of a variety of new physics
that could affect and hence be probed by solar neutrinos. After reviewing the
latest techniques and issues involved in the measurement of solar neutrino
spectra and background reduction, we provide our anticipation on the physics
gains from the new generation of neutrino experiments.
- The Status of the Galactic Center Gamma-Ray Excess
2209.14370 [abs] [pdf]
[abstract]
by Dan Hooper.
The Galactic Center Gamma-Ray Excess has a spectrum, angular distribution,
and overall intensity that agree remarkably well with that expected from
annihilating dark matter particles in the form of a $m_X \sim 50 \, {\rm GeV}$
thermal relic. Previous claims that these photons are clustered on small
angular scales or trace the distribution of known stellar populations once
appeared to favor interpretations in which this signal originates from a large
population of unresolved millisecond pulsars. More recent work, however, has
overturned these conclusions, finding that the observed gamma-ray excess does
{\it not} contain discernible small scale power, and is distributed with
approximate spherical symmetry, not tracing any known stellar populations. In
light of these results, it now appears significantly more likely that the
Galactic Center Gamma-Ray Excess is produced by annihilating dark matter.
- Non-standard neutrino interactions in light mediator models at reactor
experiments
2209.13566 [abs] [pdf]
[abstract]
by Bhaskar Dutta, [and 4 more]Sumit Ghosh, Tianjun Li, Adrian Thompson, and Ankur Verma [hide authors].
Compared to other neutrino sources, the huge anti-neutrino fluxes at nuclear
reactor based experiments empower us to derive stronger bounds on non-standard
interactions of neutrinos with electrons mediated by light scalar/vector
mediators. At neutrino energy around $200$~keV reactor anti-neutrino flux is at
least an order of magnitude larger compared to the solar flux. The atomic and
crystal form factors of the detector materials related to the details of the
atomic structure becomes relevant at this energy scale as the momentum
transfers would be small. Non-standard neutrino-electron interaction mediated
by light scalar/vector mediator arises naturally in many low-scale models. We
also propose one such new model with a light scalar mediator. Here, we
investigate the parameter space of such low-scale models in reactor based
neutrino experiments with low threshold Ge and Si detectors, and find the
prospect of probing/ruling out the relevant parameter space by finding the
projected sensitivity at $90 \%$ confidence level by performing a
$\chi^2$-analysis. We find that a detector capable of discriminating between
electron recoil and nuclear recoil signal down to a very low threshold such as
$5$~eV placed in reactor based experiment would be able to probe a larger
region in parameter space compared to the previously explored region. A Ge (Si)
detector with $10$~kg-yr exposure and 1 MW reactor anti-neutrino flux would be
able to probe the scalar and vector mediators with masses below 1 keV for
coupling products $\sqrt{g_\nu g_e}$ $\sim$ $1 \times 10^{-6}~(9.5 \times
10^{-7})$ and $1\times 10^{-7} ~(8\times 10^{-8})$, respectively.
- Neutrino non-radiative decay and the diffuse supernova neutrino
background
2209.12465 [abs] [pdf]
[abstract]
by Pilar Ivanez-Ballesteros and M. Cristina Volpe.
We revisit the possibility that neutrinos undergo non-radiative decay. We
investigate the potential to extract information on the neutrino
lifetime-to-mass ratio from the diffuse supernova neutrino background. To this
aim, we explicitly consider the current uncertainties on the core-collapse
supernova rate and the fraction of failed supernovae. We present predictions in
a full 3 neutrino framework in the absence and presence of neutrino
non-radiative decay, for the Super-Kamiokande+Gd, the JUNO, the
Hyper-Kamiokande, and the DUNE experiments, that should observe the diffuse
supernova neutrino background in the near future. Our results show the
importance of a 3 neutrino treatment of neutrino decay and of identifying the
neutrino mass ordering to break possible degeneracies between DSNB predictions
in the presence of decay and standard physics.
- Strong Supernova 1987A Constraints on Bosons Decaying to Neutrinos
2209.11773 [abs] [pdf]
[abstract]
by Damiano F. G. Fiorillo, Georg G. Raffelt, and Edoardo Vitagliano.
Majoron-like bosons would emerge from a supernova (SN) core by neutrino
coalescence of the form $\nu\nu\to\phi$ and $\bar\nu\bar\nu\to\phi$ with 100
MeV-range energies. Subsequent decays to (anti)neutrinos of all flavors provide
a flux component with energies much larger than the usual flux from the
"neutrino sphere." The absence of 100 MeV-range events in the Kamiokande-II and
Irvine-Michigan-Brookhaven signal of SN 1987A implies that less than 1% of the
total energy was thus emitted and provides the strongest constraint on the
Majoron-neutrino coupling of $g\lesssim 10^{-9}\,{\rm MeV}/m_\phi$ for
$100~{\rm eV}\lesssim m_\phi\lesssim 100~{\rm MeV}$. It is straightforward to
extend our new argument to other hypothetical feebly interacting particles.
- Determination of the total cross section and $ρ$-parameter from
elastic scattering in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS
detector
2209.11487 [abs] [pdf]
[abstract]
by Hasko Stenzel.
A new measurement of elastic $pp$ scattering at $\sqrt{s} = 13$ TeV with the
ATLAS-ALFA detector is presented. The measurement was performed using data
recorded in a special run of the LHC with $\beta^\star = 2.5$ km. The elastic
cross-section was measured differentially in the Mandelstam $t$ variable and
from a fit to ${\textrm{d}}\sigma/\textrm{d}t$ the total cross section, the
$\rho$-parameter and parameters of the nuclear slope are determined. The
results for $\sigma_{\textrm{tot}}$ and $\rho$ are \begin{equation*}
\sigma_{\textrm{tot}}(pp\rightarrow X) = \mbox{104.7} \; \pm 1.1 \; \mbox{mb} ,
\; \; \rho = \mbox{0.098} \; \pm 0.011 . \end{equation*} The energy evolution
of $\sigma_{\textrm{tot}}$ and $\rho$, connected through dispersion relations,
is compared to several models. Furthermore, the total inelastic cross section
is determined from the difference of the total and elastic cross section, and
the ratio of the elastic to total cross section is calculated.
- Probing non-unitarity of neutrino mixing in the scenario of Lorentz
violation and dark nonstandard interaction
2209.10233 [abs] [pdf]
[abstract]
by Trisha Sarkar.
Neutrino flavour oscillation is one of the primary indication of the
existence of new physics beyond standard model. The presence of small neutrino
mass is indispensable to explicate the oscillation among different flavours of
neutrino. By the addition of a right handed neutral lepton with the standard
model fermions, it is possible to generate tiny neutrino mass. Such additional
fermion may induce non-unitarity to the $3\times 3$ PMNS mixing matrix which
influences the propagation of neutrino in space-time. In this work the effect
of non-unitary mixing matrix is analyzed in neutrino oscillation in presence of
two new physics scenarios, Lorentz violation and dark non-standard interaction.
Lorentz symmetry violation mainly appears at the Planck scale, which may also
be manifested at a lower energy level. On the other hand, dark non standard
interaction arises due to the interaction of neutrino with the environmental
dark matter which contributes as a perturbative correction to the neutrino
mass. In this analysis, the comparative study of unitary and non-unitary mixing
matrix is carried out considering the scenario of Lorentz violation and dark
NSI in the context of long baseline DUNE and short baseline Daya Bay
experimental set up. The signature of dark nonstandard interaction is
observable in both DUNE and Daya Bay set up in terms of large value of neutrino
survival and oscillation probability respectively and is a possible explanation
for the excess flux observed at $\sim5$ MeV in Daya Bay experiment. The
signature of Lorentz violation is also possible to be observed in the short
baseline Daya Bay experiment only.
- Prospects for detection of a Galactic diffuse neutrino flux
2209.10011 [abs] [pdf]
[abstract]
by Pedro De la Torre Luque, Daniele Gaggero, and Dario Grasso.
A Galactic cosmic-ray transport model featuring non-homogeneous transport has
been developed over the latest years. This setup is aimed at reproducing
gamma-ray observations in different regions of the Galaxy (with particular
focus on the progressive hardening of the hadronic spectrum in the inner
Galaxy) and was shown to be compatible with the very-high-energy gamma-ray
diffuse emission recently detected up to PeV energies. In this work, we extend
the results previously presented to test the reliability of that model
throughout the whole sky. To this aim, we compare our predictions with detailed
longitude and latitude profiles of the diffuse gamma-ray emission measured by
Fermi-LAT for different energies and compute the expected Galactic neutrino
diffuse emission, comparing it with current limits from the ANTARES
collaboration. We emphasize that the possible detection of a Galactic neutrino
component will allow us to break the degeneracy between our model and other
scenarios featuring prominent contributions from unresolved sources and TeV
halos.
- Floating Dark Matter in Celestial Bodies
2209.09834 [abs] [pdf]
[abstract]
by Rebecca K. Leane and Juri Smirnov.
Dark matter (DM) can be captured in celestial bodies after scattering and
losing sufficient energy to become gravitationally bound. We derive a general
framework that describes the current DM distribution inside celestial objects,
which self-consistently includes the effects of concentration diffusion,
thermal diffusion, gravity, and capture accumulation. For DM with sufficient
interactions, we show that a significant DM population can thermalize and sit
towards the celestial-body surface. This floating distribution allows for new
phenomenology for DM searches in a wide range of celestial bodies, including
the Sun, Earth, Jupiter, Brown Dwarfs, and Exoplanets.
- Neutrino forces in neutrino backgrounds
2209.07082 [abs] [pdf]
[abstract]
by Mitrajyoti Ghosh, [and 4 more]Yuval Grossman, Walter Tangarife, Xun-Jie Xu, and Bingrong Yu [hide authors].
The Standard Model predicts a long-range force, proportional to $G_F^2/r^5$,
between fermions due to the exchange of a pair of neutrinos. This quantum force
is feeble and has not been observed yet. In this paper, we compute this force
in the presence of neutrino backgrounds, both for isotropic and directional
background neutrinos. We find that for the case of directional background the
force can have a $1/r$ dependence and it can be significantly enhanced compared
to the vacuum case. In particular, background effects caused by reactor, solar,
and supernova neutrinos enhance the force by many orders of magnitude. The
enhancement, however, occurs only in the direction parallel to the direction of
the background neutrinos. We discuss the experimental prospects of detecting
the neutrino force in neutrino backgrounds and find that the effect is close to
the available sensitivity of the current fifth force experiments. Yet, the
angular spread of the neutrino flux and that of the test masses reduce the
strength of this force. The results are encouraging and a detailed experimental
study is called for to check if the effect can be probed.
- New constraints on the dark matter-neutrino and dark matter-photon
scattering cross sections from TXS 0506+056
2209.06339 [abs] [pdf]
[abstract]
by Francesc Ferrer, Gonzalo Herrera, and Alejandro Ibarra.
The flux of high energy neutrinos and photons produced in a blazar could get
attenuated when they propagate through the dark matter spike around the central
black hole and the halo of the host galaxy. Using the observation by IceCube of
a few high-energy neutrino events from TXS 0506+056, and their coincident gamma
ray events, we obtain new constraints on the dark matter-neutrino and dark
matter-photon scattering cross sections. Our constraints are orders of
magnitude more stringent than those derived from considering the attenuation
through the intergalactic medium and the Milky Way dark matter halo. When the
cross-section increases with energy, our constraints are also stronger than
those derived from the CMB and large-scale structure.
- Probing Quantum Gravity with Elastic Interactions of Ultra-High-Energy
Neutrinos
2209.06282 [abs] [pdf]
[abstract]
by Alfonso Garcia Soto, [and 3 more]Diksha Garg, Mary Hall Reno, and Carlos A. Argüelles [hide authors].
The next generation of radio telescopes will be sensitive to low-scale
quantum gravity by measuring ultra-high-energy neutrinos. In this letter, we
demonstrate for the first time that neutrino-nucleon soft interactions induced
by TeV-scale gravity would significantly increase the number of events detected
by the IceCube-Gen2 radio array in the EeV regime. However, we show that these
experiments cannot measure the total cross section using only the angular and
energy information of the neutrino flux, unless assumptions on the underlying
inelasticity distribution of neutral interactions are made.
- Imprints of scalar NSI on the CP-violation sensitivity using synergy
among DUNE, T2HK and T2HKK
2209.05287 [abs] [pdf]
[abstract]
by Abinash Medhi, Moon Moon Devi, and Debajyoti Dutta.
The Non-Standard Interactions (NSIs) are subdominant effects, often appearing
in various extensions of SM, which may impact the neutrino oscillations through
matter. It is important and interesting to explore the impact of NSIs in the
ongoing and upcoming precise neutrino oscillations experiments. In this work,
we have studied the imprints of a scalar-mediated NSI in three upcoming
long-baseline (LBL) experiments (DUNE, T2HK, T2HKK). The effects of scalar NSI
appears as a medium-dependent correction to the neutrino mass term. Its
contribution scales linearly with matter density, making LBL experiments a
suitable candidate to probe its effects. We show that the scalar NSI may
significantly impact the oscillation probabilities, event rates at the
detectors and the $\chi^2$-sensitivities of $\delta_{CP}$ measurements. We
present the results of a combined analysis involving the LBL experiments
(DUNE+T2HK, DUNE+T2HKK, DUNE+T2HK+T2HKK) which offer a better capability of
constraining the scalar NSI parameters as well as an improved sensitivity
towards CP-violation.
- Majorana versus Dirac Constraints on the Neutrino Dipole Moments
2209.03373 [abs] [pdf]
[abstract]
by André de Gouvêa, [and 3 more]Giancarlo Jusino Sánchez, Pedro A. N. Machado, and Zahra Tabrizi [hide authors].
Massive neutrinos are guaranteed to have nonzero electromagnetic moments and,
since there are at least three neutrino species, these dipole moments define a
matrix. Here, we estimate the current upper bounds on all independent neutrino
electromagnetic moments, concentrating on Earth-bound experiments and
measurements with solar neutrinos, including the very recent results reported
by XENONnT. We make no simplifying assumptions and compare the hypotheses that
neutrinos are Majorana fermions or Dirac fermions. In particular, we fully
explore constraints in the Dirac-neutrino parameter space. Majorana and Dirac
neutrinos are different; for example, the upper bounds on the magnitudes of the
elements of the dipole moment matrix are weaker for Dirac neutrinos, relative
to Majorana neutrinos. The potential physics reach of next-generation
experiments also depends on the nature of the neutrino. We find that a
next-generation experiment two orders of magnitude more sensitive to the
neutrino electromagnetic moments via $\nu_{\mu}$ elastic scattering may
discover that the neutrino electromagnetic moments are nonzero if the neutrinos
are Dirac fermions. Instead, if the neutrinos are Majorana fermions, such a
discovery is ruled out by existing solar neutrino data, unless there are more
than three light neutrinos.
- Testing the Gallium Anomaly
2209.02885 [abs] [pdf]
[abstract]
by Patrick Huber.
We study the online detection by gallium capture of mono-energetic neutrinos
produced by a $^{51}$Cr radioactive source in a scintillation experiment. We
find that cerium-doped gadolinium aluminum gallium garnet (GAGG) is a suitable
scintillator which contains about 21% of gallium per weight and has a high mass
density and light yield. Combined with a highly efficient light detection
system this allows tagging of the subsequent germanium decay and thus a clean
distinction of gallium capture and elastic neutrino electron scattering events.
With 1.5 tons of scintillator and 10 source runs of 3.4MCi, each, we obtain
about 760 gallium capture events with a purity of 85% and 680,000 neutrino
electron scattering events, where the latter provide a precise normalization
independent of any nuclear physics. This configuration would allow to test the
gallium anomaly at more than $5\sigma$ in an independent way.
- Blazar constraints on neutrino-dark matter scattering
2209.02713 [abs] [pdf]
[abstract]
by James M. Cline, [and 7 more]Shan Gao, Fangyi Guo, Zhongan Lin, Shiyan Liu, Matteo Puel, Phillip Todd, and Tianzhuo Xiao [hide authors].
Neutrino emission in coincidence with gamma rays has been observed from the
blazar TXS 0506+056 by the IceCube telescope. Neutrinos from the blazar had to
pass through a dense spike of dark matter (DM) surrounding the central black
hole. The observation of such a neutrino implies new upper bounds on the
neutrino-DM scattering cross section as a function of DM mass. The constraint
is stronger than existing ones for a range of DM masses, if the cross section
rises linearly with energy. For constant cross sections, competitive bounds are
also possible, depending on details of the DM spike.
- Gallium Anomaly: Critical View from the Global Picture of $ν_{e}$ and
$\barν_{e}$ Disappearance
2209.00916 [abs] [pdf]
[abstract]
by C. Giunti, [and 4 more]Y. F. Li, C. A. Ternes, O. Tyagi, and Z. Xin [hide authors].
The significance of the Gallium Anomaly, from the BEST, GALLEX, and SAGE
radioactive source experiments, is quantified using different theoretical
calculations of the neutrino detection cross section, and its explanation due
to neutrino oscillations is compared with the bounds from the analyses of
reactor rate and spectral ratio data, $\beta$-decay data, and solar neutrino
data. In the 3+1 active-sterile neutrino mixing scheme, the Gallium Anomaly is
in strong tension with the individual and combined bounds of these data sets.
In the combined scenario with all available data, the parameter goodness of fit
is below 0.042%, corresponding to a severe tension of 4-5$\sigma$, or stronger.
Therefore, we conclude that one should pursue other possible solutions beyond
short-baseline oscillations for the Gallium Anomaly. We also present a new
global fit of $\nu_e$ and $\bar\nu_e$ disappearance data, showing that there is
a 2.6-3.3$\sigma$ preference in favor of short-baseline oscillations, which is
driven by an updated analysis of reactor spectral ratio data.
- Comment on "Damping of neutrino oscillations, decoherence and the
lengths of neutrino wave packets''
2209.00561 [abs] [pdf]
[abstract]
by B. J. P. Jones.
We point out three apparent inconsistencies in the treatment of oscillation
coherence from reactor neutrino and source neutrino experiments in recent paper
"Damping of neutrino oscillations, decoherence and the lengths of neutrino wave
packets''. First, that the dependence of the oscillation probability upon the
subsequent interactions of entangled recoil particles implies causality
violations and in some situations superluminal signaling; second, that
integrating over a non-orthogonal basis for the entangled recoil leads to
unphysical effects; and third, that the question of what interactions serve to
measure the position of the initial state particle remains ambiguous. These
points taken together appear to undermine the claim made therein that the
effects of wave packet separation must be strictly unobservable in reactor and
radioactive source based neutrino experiments.
- Characterising Dark Matter-induced neutrino potentials
2209.00442 [abs] [pdf]
[abstract]
by Gabriel M. Salla.
In this paper we explore interactions between neutrinos and Dark Matter. In
particular, we study how the propagation of astrophysical neutrinos can be
modified by computing the most general potential generated by the galactic DM
background. We use on-shell techniques to compute this potential in a
completely model independent way and obtain an expression valid for any Dark
Matter mass and spin. Afterwards, we use this expression to analyse under what
circumstances such potential can be important at the phenomenological level,
and we find that under some assumptions only ultra light scalar Dark Matter
could be of any relevance to oscillation experiments.
August 2022
- Addressing the Short-Baseline Neutrino Anomalies with Energy-Dependent
Mixing Parameters
2209.00031 [abs] [pdf]
[abstract]
by K. S. Babu, [and 3 more]Vedran Brdar, André de Gouvêa, and Pedro A. N. Machado [hide authors].
Several neutrino experiments have reported results that are potentially
inconsistent with our current understanding of the lepton sector. A candidate
solution to these so-called short-baseline anomalies is postulating the
existence of new, eV-scale, mostly sterile neutrinos that mix with the active
neutrinos. This hypothesis, however, is strongly disfavored once one considers
all neutrino data, especially those that constrain the disappearance of muon
and electron neutrinos at short-baselines. Here, we show that if the
sterile-active mixing parameters depend on the energy-scales that characterize
neutrino production and detection, the sterile-neutrino hypothesis may provide
a reasonable fit to all neutrino data. The reason for the improved fit is that
the stringent disappearance constraints on the different elements of the
extended neutrino mixing matrix are associated to production and detection
energy scales that are different from those that characterize the anomalous
LSND and MiniBooNE appearance data. We show, via a concrete example, that
secret interactions among the sterile neutrinos can lead to the results of
interest.
- Exploiting stellar explosion induced by the QCD phase transition in
large-scale neutrino detectors
2208.14469 [abs] [pdf]
[abstract]
by Tetyana Pitik, [and 3 more]Daniel Heimsoth, Anna M. Suliga, and A. B. Balantekin [hide authors].
The centers of the core-collapse supernovae are one of the densest
environments in the Universe. Under such conditions, it is conceivable that a
first-order phase transition from ordinary nuclear matter to the quark-gluon
plasma occurs. This transition releases a large amount of latent heat that can
drive a supernova explosion and may imprint a sharp signature in the neutrino
signal. We show how this snap feature, if observed at large-scale neutrino
detectors, can set competitive limits on the neutrino masses and assist the
localization of the supernova via triangulation. The 95\%C.L. limit on the
neutrino mass can reach 0.16~eV in Ice-Cube, 0.22~eV in Hyper-Kamiokande, and
0.58~eV in DUNE, for a supernova at a distance of 10 kpc. For the same distance
and in the most optimistic neutrino conversion case, the triangulation method
can constrain the $1\sigma$ angular uncertainty of the supernova localization
within $\sim 0.3^{\circ}-9.0^{\circ}$ in the considered pairs of the detectors,
leading to an improvement up to an order of magnitude with respect to the often
considered in the literature rise time of the neutronization burst.
- Physics implications of recent Dresden-II reactor data
2208.13262 [abs] [pdf]
[abstract]
by Anirban Majumdar, [and 3 more]Dimitrios K. Papoulias, Rahul Srivastava, and José W. F. Valle [hide authors].
Prompted by the recent Dresden-II reactor data we examine its implications
for the determination of the weak mixing angle, paying attention to the effect
of the quenching function. We also determine the resulting constraints on the
unitarity of the neutrino mixing matrix, as well as on the most general type of
nonstandard neutral-current neutrino interactions.
- Constraining Non-Standard Interactions with Coherent Elastic
Neutrino-Nucleus Scattering at the European Spallation Source
2208.11771 [abs] [pdf]
[abstract]
by Sabya Sachi Chatterjee, [and 3 more]Stéphane Lavignac, O. G. Miranda, and G. Sanchez Garcia [hide authors].
The European Spallation Source (ESS), currently under construction in Sweden,
will provide an intense pulsed neutrino flux allowing for high-statistics
measurements of coherent elastic neutrino-nucleus scattering (CE{\nu}NS) with
advanced nuclear recoil detectors. In this paper, we investigate in detail the
possibility of constraining non-standard neutrino interactions (NSIs) through
such precision CE{\nu}NS measurements at the ESS, considering the different
proposed detection technologies, either alone or in combination. We first study
the sensitivity to neutral-current NSI parameters that each detector can reach
in 3 years of data taking. We then show that operating two detectors
simultaneously can significantly improve the expected sensitivity on
flavor-diagonal NSI parameters. Combining the results of two detectors turns
out to be even more useful when two NSI parameters are assumed to be
nonvanishing at a time. In this case, suitably chosen detector combinations can
reduce the degeneracies between some pairs of NSI parameters to a small region
of the parameter space.
- Quantum Gravitational Decoherence in the 3 Neutrino Flavor Scheme
2208.11754 [abs] [pdf]
[abstract]
by Dominik Hellmann, Heinrich Päs, and Erika Rani.
In many theories of quantum gravity quantum fluctuations of spacetime may
serve as an environment for decoherence. Here we study quantum-gravitational
decoherence of high energy astrophysical neutrinos in the presence of fermionic
dark sectors and for a realistic three neutrino scenario. We show how violation
of global symmetries expected to arise in quantum gravitational interactions
provides a possibility to pin down the number of dark matter fermions in the
universe. Furthermore, we predict the expected total neutrino flux and flavor
ratios at experiments depending on the flavor composition at the source.
- Probing neutrino interactions and dark radiation with gravitational
waves
2208.11714 [abs] [pdf]
[abstract]
by Marilena Loverde and Zachary J. Weiner.
After their generation, cosmological backgrounds of gravitational waves
propagate nearly freely but for the expansion of the Universe and the
anisotropic stress of free-streaming particles. Primordial signals -- both that
from inflation and the infrared spectrum associated to subhorizon production
mechanisms -- would carry clean information about the cosmological history of
these effects. We study the modulation of the standard damping of gravitational
waves by free-streaming radiation due to the decoupling (or recoupling) of
interactions. We focus on nonstandard neutrino interactions in effect after the
decoupling of weak interactions as well as more general scenarios in the early
Universe involving other light relics. We develop semianalytic results in fully
free-streaming scenarios to provide intuition for numerical results that
incorporate interaction rates with a variety of temerpature dependencies.
Finally, we compute the imprint of neutrino interactions on the $B$-mode
polarization of the cosmic microwave background, and we comment on other means
to infer the presence of such effects at higher frequencies.
- Recent results from the TOTEM collaboration and the discovery of the
odderon
2208.10782 [abs] [pdf]
[abstract]
by C. Royon.
We describe the most recent results from the TOTEM collaboration on elastic,
inelastic and total cross sections as well as the odderon discovery by the D0
and TOTEM collaborations.
- The carbon footprint of proposed $\rm e^+e^-$ Higgs factories
2208.10466 [abs] [pdf]
[abstract]
by Patrick Janot and Alain Blondel.
The energy consumption of any of the $\rm e^+e^-$ Higgs factory projects that
can credibly operate immediately after the end of LHC, namely three linear
colliders (CLIC, operating at $\sqrt{s}=380$GeV; and ILC and $\rm C^3$,
operating at $\sqrt{s}=250$ GeV) and two circular colliders (CEPC and FCC-ee,
operating at $\sqrt{s}=240$ GeV), will be everything but negligible. Future
Higgs boson studies may therefore have a significant environmental impact. This
note proposes to include the carbon footprint for a given physics performance
as a top-level gauge for the design optimization and, eventually, the choice of
the future facility. The projected footprints per Higgs boson produced,
evaluated using the 2021 carbon emission of available electricity, are found to
vary by a factor 100 depending on the considered Higgs factory project.
- Texture of Two Vanishing Subtraces in Neutrino Mass Matrix and Current
Experimental Tests
2208.10344 [abs] [pdf]
[abstract]
by A. Ismael, E. I. Lashin, and N. Chamoun.
We present a full phenomenological and analytical study for the neutrino mass
matrix characterized by two vanishing $2\times2$ subtraces. We update one past
result in light of the recent experimental data. Out of the fifteen possible
textures, we find seven cases can accommodate the experimental data instead of
eight ones in the past study. We also introduce few symmetry realizations for
viable and nonviable textures based on non-abelian ($A_4$ or $S_4$) flavor
symmetry within type II seesaw scenario.
- Discovering neutrinoless double-beta decay in the era of precision
neutrino cosmology
2208.09954 [abs] [pdf]
[abstract]
by Manuel Ettengruber, [and 4 more]Matteo Agostini, Allen Caldwell, Philipp Eller, and Oliver Schulz [hide authors].
We evaluate the discovery probability of a combined analysis of proposed
neutrinoless double-beta decay experiments in a scenario with normal ordered
neutrino masses. The discovery probability strongly depends on the value of the
lightest neutrino mass, ranging from zero in case of vanishing masses and up to
80-90\% for values just below the current constraints. We study the discovery
probability in different scenarios, focusing on the exciting prospect in which
cosmological surveys will measure the sum of neutrino masses. Uncertainties in
nuclear matrix element calculations partially compensate each other when data
from different isotopes are available. Although a discovery is not granted, the
theoretical motivations for these searches and the presence of scenarios with
high discovery probability strongly motivates the proposed international,
multi-isotope experimental program.
- Zoom in muon survival probability with sterile neutrino for CP and
T-violation
2208.09696 [abs] [pdf]
[abstract]
by Kiran Sharma and Sudhanwa Patra.
We present the approximated analytic expressions for the muon survival
probability in a $3+1$ mixing scenario in the presence of matter effect using
the S-matrix formalism. We find that all the individual terms contributing to
the muon survival probability can significantly reduce to just three
contributions. The leading order contribution comes from the three flavor muon
survival probability followed by the two sub-leading contributions arising from
active-sterile mixing. Furthermore, to more simplify the results we adopt the
well known series expansion relations about mass-hierarchy parameter $\alpha =
\Delta m^2_{21} / \Delta m^2_{31}$ and the mixing angle $\sin \theta_{13}$ in
the vanishing limit of $\alpha^2$. We discuss the relevance of muon survival
probability to probe the CP and T-violation studies coming from the new
physics. We also compare the analytic relation between vacuum and matter
contributions to the muon survival probability at the leading order. Finally,
we comment on the probability behavior at the various long baselines relevant
to understand the atmospheric-neutrino sector and to resolve the existing
mass-hierarchy problem.
- Extra dimensions with light and heavy neutral leptons: An application to
CE$ν$NS
2208.09584 [abs] [pdf]
[abstract]
by Amir N. Khan.
We explore the possibility of relating extra dimensions with light and heavy
Dirac-type neutral leptons and develop a framework for testing them in various
laboratory experiments. The Kaluza-Klein modes in the large extra dimension
models of the light neutral leptons could mix with the standard model neutrinos
and produce observable effects in the oscillation experiments. We show that the
chirality flipping up-scattering processes occurring through either neutrino
magnetic dipole moment or the weakly coupled scalar interactions can also
produce heavy Kaluza-Klein modes of the corresponding right-handed neutral
leptons propagating in one or more extra dimensions. However, to conserve the
four-dimensional energy-momentum, their masses must be below the maximum energy
of the neutrinos in the initial state. The appreciable size of extra dimensions
connected with these heavy neutral leptons can thus affect the cross-sections
of these processes. This framework applies to any up-scattering process. Our
work here focuses only on its application to the coherent elastic
neutrino-nucleus scattering process. We derive constraints on the size of extra
dimensions using the COHERENT data in oscillation and up-scattering processes.
For model with one large extra dimension for the light neutral leptons, we
obtain the limits, $R \sim 3 \ \mu$m (NH) and $R \sim 2.5 \ \mu$m (IH), on the
size of extra dimension corresponding to the absolute mass limit, $m_{0} \leq 3
\times 10^{-3}$ eV at 90$\%$ C.L. from the short-baseline oscillations. Using
the up-scattering process for heavy neutral leptons, we obtain new parameter
spaces between the size of extra dimensions and parameters of the dipole or
scalar interactions.
- $E_{\mathrm{iso}}$-$E_{\mathrm{p}}$ correlation of gamma ray bursts:
calibration and cosmological applications
2208.09272 [abs] [pdf]
[abstract]
by X. D. Jia, [and 4 more]J. P. Hu, J. Yang, B. B. Zhang, and F. Y. Wang [hide authors].
Gamma-ray bursts (GRBs) are the most explosive phenomena and can be used to
study the expansion of Universe. In this paper, we compile a long GRB sample
for the $E_{\mathrm{iso}}$-$E_{\mathrm{p}}$ correlation from Swift and Fermi
observations. The sample contains 221 long GRBs with redshifts from 0.03 to
8.20. From the analysis of data in different redshift intervals, we find no
statistically significant evidence for the redshift evolution of this
correlation. Then we calibrate the correlation in six sub-samples and use the
calibrated one to constrain cosmological parameters. Employing a piece-wise
approach, we study the redshift evolution of dark energy equation of state
(EOS), and find that the EOS tends to be oscillating at low redshift, but
consistent with $-1$ at high redshift. It hints a dynamical dark energy at
$2\sigma$ confidence level at low redshift.
- UHE neutrinos encountering decaying and non-decaying magnetic fields of
compact stars
2208.06644 [abs] [pdf]
[abstract]
by Neetu Raj Singh Chundawat, Arindam Mandal, and Trisha Sarkar.
The phenomena of neutrino spin flavour precession in the presence of an
extraneous magnetic field is a repercussion of neutrino magnetic moment which
is consociated with the physics beyond the standard model of electroweak
interactions. Ultra high energy neutrinos are spawned from a number of sources
in the universe including the highly energetic astrophysical objects such as
active galactic nuclei, blazar or supermassive black holes. When such high
energy neutrinos pass through any compact stellar objects like neutron stars or
white dwarfs, their flux can significantly reduce due to the exorbitant
magnetic field provided by these compact objects. For Dirac neutrinos, such
phenomena occur due to the conversion of neutrinos to their sterile
counterparts. In this work, we consider a neutron star possessing a spatially
varying magnetic field which may or may not decay with time. We find that, for
the non-decaying magnetic field, the flux of high energy Dirac neutrinos
becomes nearly half after passing through the neutron star. The flux is further
enfeebled by $\sim 10\%$ in the presence of muons inside the neutron star. For
decaying magnetic field, the flux reduction is abated by $\sim 5\%$ as compared
to the temporally static magnetic field. In the case of a white dwarf, the
depletion of flux is lesser as compared to the neutron stars.
- Ultra-high energy neutrinos from high-redshift electromagnetic cascades
2208.06440 [abs] [pdf]
[abstract]
by AmirFarzan Esmaeili, [and 3 more]Antonio Capanema, Arman Esmaili, and Pasquale Dario Serpico [hide authors].
We study the impact of the muon pair production and double pair production
processes induced by ultra-high energy photons on the cosmic microwave
background. Although the muon pair production cross section is smaller than the
electron pair production one, the associated energy loss length is comparable
or shorter than the latter (followed by inverse Compton in the deep
Klein-Nishina regime) at high-redshift, where the effect of the astrophysical
radio background is expected to be negligible. By performing a simulation
taking into account the details of $e/\gamma$ interactions at high energies, we
show that a significant fraction of the electromagnetic energy injected at
$E\gtrsim 10^{19}\,$eV at redshift $z\gtrsim 5$ is channeled into neutrinos.
The double pair production plays a crucial role in enhancing the multiplicity
of muon production in these electromagnetic cascades. The ultra-high energy
neutrino spectrum, yet to be detected, can in principle harbour information on
ultra-high energy sources in the young universe, either conventional or exotic
ones, with weaker constraints from the diffuse gamma ray flux compared to their
low redshift counterparts.
- Implications of first LZ and XENONnT results: A comparative study of
neutrino properties and light mediators
2208.06415 [abs] [pdf]
[abstract]
by ShivaSankar K. A., [and 4 more]Anirban Majumdar, Dimitrios K. Papoulias, Hemant Prajapati, and Rahul Srivastava [hide authors].
Next generation direct dark matter detection experiments are favorable
facilities to probe neutrino properties and light mediators beyond the Standard
Model. We explore the implications of the recent data reported by LUX-ZEPLIN
(LZ) and XENONnT collaborations on electromagnetic neutrino interactions and
neutrino generalized interactions (NGIs). We show that XENONnT places the most
stringent upper limits on the effective and transition neutrino magnetic moment
(of the order of few $\times 10^{-12}~\mu_B$) as well as stringent constraints
to neutrino millicharge (of the order of $\sim 10^{-13}~e$)--competitive to
LZ--and improved by about one order of magnitude in comparison to existing
constraints coming from Borexino and TEXONO. We furthermore explore the XENONnT
and LZ sensitivities to simplified models with light NGIs and find improved
constraints in comparison to those extracted from Borexino-Phase II data.
- Evidence for PeV Proton Acceleration from Fermi-LAT Observations of SNR
G106.3+2.7
2208.05457 [abs] [pdf]
[abstract]
by Ke Fang, [and 4 more]Matthew Kerr, Roger Blandford, Henrike Fleischhack, and Eric Charles [hide authors].
The existence of a "knee" at energy ~1 PeV in the cosmic-ray spectrum
suggests the presence of Galactic PeV proton accelerators called "PeVatrons".
Supernova Remnant (SNR) G106.3+2.7 is a prime candidate for one of these. The
recent detection of very high energy (0.1-100 TeV) gamma rays from G106.3+2.7
may be explained either by the decay of neutral pions or inverse Compton
scattering by relativistic electrons. We report an analysis of 12 years of
Fermi-LAT gamma-ray data which shows that the GeV-TeV gamma-ray spectrum is
much harder and requires a different total electron energy than the radio and
X-ray spectra, suggesting it has a distinct, hadronic origin. The non-detection
of gamma rays below 10 GeV implies additional constraints on the relativistic
electron spectrum. A hadronic interpretation of the observed gamma rays is
strongly supported. This observation confirms the long-sought connection
between Galactic PeVatrons and SNRs. Moreover, it suggests that G106.3+2.7
could be the brightest member of a new population of SNRs whose gamma-ray
energy flux peaks at TeV energies. Such a population may contribute to the
cosmic-ray knee and be revealed by future very high energy gamma-ray detectors.
- Implications of the QCD dynamics and a Super-Glashow astrophysical
neutrino flux on the description of ultrahigh energy neutrino data
2208.04597 [abs] [pdf]
[abstract]
by Victor P. Goncalves, Diego R. Gratieri, and Alex S. C. Quadros.
The number of events observed in neutrino telescopes depends on the neutrino
fluxes in the Earth, their absorption while crossing the Earth and their
interaction in the detector. In this paper, we investigate the impact of the
QCD dynamics at high energies on the energy dependence of the average
inelasticity and angular dependence of the absorption probability during the
neutrino propagation through the Earth, as well in the determination of the
properties of the incident astrophysical neutrino flux. Moreover, the number of
events at the IceCube and IceCube - Gen2 are estimated considering different
scenarios for the QCD dynamics and assuming the presence of a hypothetical
Super - Glashow flux, which peaks for energies above the Glashow resonance.
- Neutrino Decoherence and the Mass Hierarchy in the JUNO Experiment
2208.04277 [abs] [pdf]
[abstract]
by Eric Marzec and Joshua Spitz.
The finite size of a neutrino wavepacket at creation can affect its
oscillation probability. Here, we consider the electron antineutrino wavepacket
and decoherence in the context of the nuclear reactor based experiment JUNO.
Given JUNO's high expected statistics [$\sim$100k IBD events ($\bar{\nu}_e p
\rightarrow e^+ n$)], long baseline ($\sim$53\,km), and excellent energy
resolution [$\sim$$0.03/\sqrt{E_{\mathrm{vis}}~\mathrm{(MeV)}}$], its
sensitivity to the size of the wavepacket is expected to be quite strong.
Unfortunately, this sensitivity may weaken the experiment's ability to measure
the orientation of the neutrino mass hierarchy for currently allowed values of
the wavepacket size. Here, we report both the JUNO experiment's ability to
determine the hierarchy orientation in the presence of a finite wavepacket and
its simultaneous sensitivity to size of the wavepacket and the hierarchy. We
find that wavepacket effects are relevant for the hierarchy determination up to
nearly two orders of magnitude above the current experimental lower limit on
the size, noting that there is no theoretical consensus on the expectation of
this value. We also consider the effect in the context of other aspects of
JUNO's nominal three-neutrino oscillation measurement physics program and the
prospect of future enhancements to sensitivity, including from precise
measurements of $\Delta m^2_{3l}$ and a near detector.
- Implications of Recent KATRIN Results for Lower-Limits on Neutrino
Masses
2208.03790 [abs] [pdf]
[abstract]
by Ephraim Fischbach, [and 3 more]Dennis E. Krause, Quan Le Thien, and Carol Scarlett [hide authors].
Recently announced results from the KATRIN collaboration imply an upper bound
on the effective electron anti-neutrino mass $m_{\nu_{e}}$, $m_{\nu_{e}}<
0.8~{\rm eV}/c^{2}$. Here we explore the implications of combining the KATRIN
upper bound using a previously inferred lower bound on the smallest neutrino
mass state, $m_{i,{\rm min}}\gtrsim 0.4~{\rm eV}/c^{2}$ implied by the
stability of white dwarfs and neutron stars in the presence of long-range
many-body neutrino-exchange forces. By combining a revised lower bound estimate
with the expected final upper bound from KATRIN, we find that the available
parameter space for $m_{\nu_{e}}$ may be closed completely within the next few
years. We then extend the argument when a single light sterile neutrino flavor
is present to set a lower mass limit on sterile neutrinos.
- Damping of neutrino oscillations, decoherence and the lengths of
neutrino wave packets
2208.03736 [abs] [pdf]
[abstract]
by Evgeny Akhmedov and Alexei Y. Smirnov.
Spatial separation of the wave packets (WPs) of neutrino mass eigenstates
leads to decoherence and damping of neutrino oscillations. Damping can also be
caused by finite energy resolution of neutrino detectors or, in the case of
experiments with radioactive neutrino sources, by finite width of the emitted
neutrino line. We study in detail these two types of damping effects using
reactor neutrino experiments and experiments with radioactive $^{51}$Cr source
as examples. We demonstrate that the effects of decoherence by WP separation
can always be incorporated into a modification of the energy resolution
function of the detector and so are intimately entangled with it. We estimate
for the first time the lengths $\sigma_x$ of WPs of reactor neutrinos and
neutrinos from a radioactive $^{51}$Cr source. The obtained values, $\sigma_x =
(2\times 10^{-5} - 1.4\times 10^{-4})$ cm, are at least six orders of magnitude
larger than the currently available experimental lower bounds. We conclude that
effects of decoherence by WP separation cannot be probed in reactor and
radioactive source experiments.
- Impact of Nuclear effects in Energy Reconstruction Methods on
Sensitivity of Neutrino Oscillation Parameters at NO$ν$A experiment
2208.03681 [abs] [pdf]
[abstract]
by Paramita Deka, Jaydip Singh, and Kalpana Bora.
Long baseline (LBL) neutrino experiments aim to measure the neutrino
oscillation parameters to high precision. These experiments use nuclear targets
for neutrino scattering and hence are inflicted with complexities of nuclear
effects. Nuclear effects and their percolation into sensitivity measurement of
neutrino oscillations parameters are not yet fully understood and therefore
need to be dealt with carefully. In a recent work [1], we reported some results
on this for NO$\nu$A experiment using the kinematic method of neutrino energy
reconstruction, where it was observed that the nuclear effects are important in
sensitivity analysis, and inclusion of realistic detector setup specifications
increases uncertainty in this analysis as compared to ideal detector case. With
this motivation, in this work, we use two methods of neutrino energy
reconstruction - kinematic and calorimetric, including the nuclear effects, and
study their impact on sensitivity analysis. We consider nuclear interactions
such as RPA and 2p2h and compare two energy reconstruction methods with
reference to events generation, measurement of neutrino oscillation parameters
$\Delta m_{32}^2$ and $\theta_{23}$ for disappearance channel, mass hierarchy
sensitivity, and CP-violation sensitivity for appearance channel of the
NO$\nu$A experiment. It is observed that with an ideal detector setup, the
kinematic method shows significant dependence on nuclear effects compared to
the calorimetric method. We also investigate the impact of realistic detector
setup for NO$\nu$A in these two methods (with nuclear effects) and find that
the calorimetric method shows more bias (uncertainty increases) in sensitivity
contours, as compared to the kinematic method. This is found to be true for
both the mass hierarchies and for both neutrino and antineutrino incoming
beams.
- Bounds on ultralight bosons from the Event Horizon Telescope observation
of Sgr A$^*$
2208.03530 [abs] [pdf]
[abstract]
by Akash Kumar Saha, [and 5 more]Priyank Parashari, Tarak Nath Maity, Abhishek Dubey, Subhadip Bouri, and Ranjan Laha [hide authors].
Recent observation of Sagittarius A$^*$ (Sgr A$^*$) by the Event Horizon
Telescope (EHT) collaboration has uncovered various unanswered questions in
black hole (BH) physics. Besides, it may also probe various beyond the Standard
Model (BSM) scenarios. One of the most profound possibilities is the search for
ultralight bosons (ULBs) using BH superradiance (SR). EHT observations imply
that Sgr A$^*$ has a non-zero spin. Using this observation, we derive bounds on
the mass of ULBs with purely gravitational interactions. Considering
self-interacting ultralight axions, we constrain new regions in the parameter
space of decay constant, for a certain spin of Sgr A$^*$. Future observations
of various spinning BHs can improve the present constraints on ULBs.
July 2022
- Unveiling the outer core composition with neutrino oscillation
tomography
2208.00532 [abs] [pdf]
[abstract]
by L. Maderer, [and 4 more]E. Kaminski, J. A. B. Coelho, S. Bourret, and V. Van Elewyck [hide authors].
In the last 70 years, geophysics has established that the Earth's outer core
is an FeNi alloy containing a few percent of light elements, whose nature and
amount remain controversial today. Besides the classical combinations of
silicon and oxygen, hydrogen has been advocated as the only light element that
could account alone for both the density and velocity profiles of the outer
core. Here we show how this question can be addressed from an independant
viewpoint, by exploiting the tomographic information provided by atmospheric
neutrinos, weakly-interacting particles produced in the atmosphere and
constantly traversing the Earth. We evaluate the potential of the upcoming
generation of atmospheric neutrino detectors for such a measurement, showing
that they could efficiently detect the presence of 1 wt% of hydrogen in an FeNi
core in 50 years of concomitant data taking. We then identify the main
requirements for a next-generation detector to perform this measurement in a
few years timescale, with the further capability to efficiently discriminate
between FeNiH and FeNiSi(x)O(y) models in less than 15 years.
- The brightest galaxies at Cosmic Dawn
2207.14808 [abs] [pdf]
[abstract]
by Charlotte A. Mason, Michele Trenti, and Tommaso Treu.
Recent JWST observations suggest an excess of $z\gtrsim10$ galaxy candidates
above most theoretical models. Here, we explore how the interplay between halo
formation timescales, star formation efficiency and dust attenuation affects
the properties and number densities of galaxies we can detect in the early
universe. We calculate the theoretical upper limit on the UV luminosity
function, assuming star formation is 100% efficient and all gas in halos is
converted into stars, and that galaxies are at the peak age for UV emission
(~10 Myr). This upper limit is ~4 orders of magnitude greater than current
observations, implying these are fully consistent with star formation in
$\Lambda$CDM cosmology. In a more realistic model, we use the distribution of
halo formation timescales derived from extended Press-Schechter theory as a
proxy for star formation rate (SFR). We predict that the galaxies observed so
far at $z\gtrsim10$ are dominated by those with the fastest formation
timescales, and thus most extreme SFRs and young ages. These galaxies can be
upscattered by ~1.5 mag compared to the median UV magnitude vs halo mass
relation. This likely introduces a selection effect at high redshift whereby
only the youngest ($\lesssim$10 Myr), most highly star forming galaxies
(specific SFR$\gtrsim$30 Gyr$^{-1}$) have been detected so far. Furthermore,
our modelling suggests that redshift evolution at the bright end of the UV
luminosity function is substantially affected by the build-up of dust
attenuation. We predict that deeper JWST observations (reaching m~30) will
reveal more typical galaxies with relatively older ages (~100 Myr) and less
extreme specific SFRs (~10 Gyr$^{-1}$ for a $M_\mathrm{UV}$ ~ -20 galaxy at
z~10).
- Enhanced Small-Scale Structure in the Cosmic Dark Ages
2207.14735 [abs] [pdf]
[abstract]
by Derek Inman and Kazunori Kohri.
We consider the consequences of a matter power spectrum which rises on small
scales until eventually being cutoff by microphysical processes associated with
the particle nature of dark matter. Evolving the perturbations of a weakly
interacting massive particle from before decoupling until deep in the nonlinear
regime, we show that nonlinear structure can form abundantly at very high
redshifts. In such a scenario, dark matter annihilation is substantially
increased after matter-radiation equality. Furthermore, since the power
spectrum can be increased over a broad range of scales, the first star forming
halos may form earlier than usual as well. The next challenge is determining
how early Universe observations may constrain such enhanced dark matter
perturbations.
- The Profiled Feldman-Cousins technique for confidence interval
construction in the presence of nuisance parameters
2207.14353 [abs] [pdf]
[abstract]
by M. A. Acero, [and 220 more]B. Acharya, P. Adamson, L. Aliaga, N. Anfimov, A. Antoshkin, E. Arrieta-Diaz, L. Asquith, A. Aurisano, A. Back, C. Backhouse, M. Baird, N. Balashov, P. Baldi, B. A. Bambah, S. Bashar, A. Bat, K. Bays, R. Bernstein, V. Bhatnagar, D. Bhattarai, B. Bhuyan, J. Bian, A. C. Booth, R. Bowles, B. Brahma, C. Bromberg, N. Buchanan, A. Butkevich, S. Calvez, T. J. Carroll, E. Catano-Mur, A. Chatla, R. Chirco, B. C. Choudhary, S. Choudhary, A. Christensen, T. E. Coan, M. Colo, L. Cremonesi, G. S. Davies, P. F. Derwent, P. Ding, Z. Djurcic, M. Dolce, D. Doyle, D. Dueñas Tonguino, E. C. Dukes, A. Dye, R. Ehrlich, M. Elkins, E. Ewart, G. J. Feldman, P. Filip, J. Franc, M. J. Frank, H. R. Gallagher, R. Gandrajula, F. Gao, A. Giri, R. A. Gomes, M. C. Goodman, V. Grichine, M. Groh, R. Group, B. Guo, A. Habig, F. Hakl, A. Hall, J. Hartnell, R. Hatcher, H. Hausner, M. He, K. Heller, V Hewes, A. Himmel, B. Jargowsky, J. Jarosz, F. Jediny, C. Johnson, M. Judah, I. Kakorin, D. M. Kaplan, A. Kalitkina, J. Kleykamp, O. Klimov, L. W. Koerner, L. Kolupaeva, S. Kotelnikov, R. Kralik, Ch. Kullenberg, M. Kubu, A. Kumar, C. D. Kuruppu, V. Kus, T. Lackey, K. Lang, P. Lasorak, J. Lesmeister, S. Lin, A. Lister, J. Liu, M. Lokajicek, J. M. C. Lopez, R. Mahji, S. Magill, M. Manrique Plata, W. A. Mann, M. T. Manoharan, M. L. Marshak, M. Martinez-Casales, V. Matveev, B. Mayes, B. Mehta, M. D. Messier, H. Meyer, T. Miao, V. Mikola, W. H. Miller, S. Mishra, S. R. Mishra, A. Mislivec, R. Mohanta, A. Moren, A. Morozova, W. Mu, L. Mualem, M. Muether, K. Mulder, D. Naples, A. Nath, N. Nayak, S. Nelleri, J. K. Nelson, R. Nichol, E. Niner, A. Norman, A. Norrick, T. Nosek, H. Oh, A. Olshevskiy, T. Olson, J. Ott, A. Pal, J. Paley, L. Panda, R. B. Patterson, G. Pawloski, D. Pershey, O. Petrova, R. Petti, D. D. Phan, R. K. Plunkett, A. Pobedimov, J. C. C. Porter, A. Rafique, L. R. Prais, V. Raj, M. Rajaoalisoa, B. Ramson, B. Rebel, P. Rojas, P. Roy, V. Ryabov, O. Samoylov, M. C. Sanchez, S. Sánchez Falero, P. Shanahan, P. Sharma, S. Shukla, A. Sheshukov, I. Singh, P. Singh, V. Singh, E. Smith, J. Smolik, P. Snopok, N. Solomey, A. Sousa, K. Soustruznik, M. Strait, L. Suter, A. Sutton, S. Swain, C. Sweeney, A. Sztuc, B. Tapia Oregui, P. Tas, B. N. Temizel, T. Thakore, R. B. Thayyullathil, J. Thomas, E. Tiras, J. Tripathi, J. Trokan-Tenorio, Y. Torun, J. Urheim, P. Vahle, Z. Vallari, J. Vasel, T. Vrba, M. Wallbank, T. K. Warburton, M. Wetstein, D. Whittington, D. A. Wickremasinghe, T. Wieber, J. Wolcott, M. Wrobel, W. Wu, Y. Xiao, B. Yaeggy, A. Yallappa Dombara, A. Yankelevich, K. Yonehara, S. Yu, Y. Yu, S. Zadorozhnyy, J. Zalesak, Y. Zhang, and R. Zwaska [hide authors].
Measuring observables to constrain models using maximum-likelihood estimation
is fundamental to many physics experiments. The Profiled Feldman-Cousins method
described here is a potential solution to common challenges faced in
constructing accurate confidence intervals: small datasets, bounded parameters,
and the need to properly handle nuisance parameters. This method achieves more
accurate frequentist coverage than other methods in use, and is generally
applicable to the problem of parameter estimation in neutrino oscillations and
similar measurements. We describe an implementation of this method in the
context of the NOvA experiment.
- Unravelling the formation of the first supermassive black holes with the
SKA pulsar timing array
2207.14309 [abs] [pdf]
[abstract]
by Hamsa Padmanabhan and Abraham Loeb.
Galaxy mergers at high redshifts trigger the activity of their central
supermassive black holes, eventually also leading to their coalescence -- and a
potential source of low-frequency gravitational waves detectable by the SKA
Pulsar Timing Array (PTA). Two key parameters related to the fuelling of black
holes are the Eddington ratio of quasar accretion $\eta_{\rm Edd}$, and the
radiative efficiency of the accretion process, $\epsilon$ (which affects the
so-called active lifetime of the quasar, $t_{\rm QSO}$). We forecast the regime
of detectability of gravitational wave events with SKA PTA, finding the
associated binaries to have orbital periods on the order of weeks to years,
observable through relativistic Doppler velocity boosting and/or optical
variability of their light curves. Combining the SKA regime of detectability
with the latest observational constraints on high-redshift black hole mass and
luminosity functions, and theoretically motivated prescriptions for the merger
rates of dark matter haloes, we forecast the number of active counterparts of
SKA PTA events expected as a function of primary black hole mass at $z \gtrsim
6$. We find that the quasar counterpart of the most massive black holes will be
${uniquely \ localizable}$ within the SKA PTA error ellipse at $z \gtrsim 6$.
We also forecast the number of expected counterparts as a function of the
quasars' Eddington ratio and active lifetime. Our results show that SKA PTA
detections can place robust constraints on the seeding and growth mechanisms of
the first supermassive black holes.
- Jupiter missions as probes of dark matter
2207.13709 [abs] [pdf]
[abstract]
by Lingfeng Li and JiJi Fan.
Jupiter, the fascinating largest planet in the solar system, has been visited
by nine spacecraft, which have collected a significant amount of data about
Jovian properties. In this paper, we show that one type of the in situ
measurements on the relativistic electron fluxes could be used to probe dark
matter (DM) and dark mediator between the dark sector and our visible world.
Jupiter, with its immense weight and cool core, could be an ideal capturer for
DM with masses around the GeV scale. The captured DM particles could annihilate
into long-lived dark mediators such as dark photons, which subsequently decay
into electrons and positrons outside Jupiter. The charged particles, trapped by
the Jovian magnetic field, have been measured in Jupiter missions such as the
Galileo probe and the Juno orbiter. We use the data available to set upper
bounds on the cross section of DM scattering off nucleons, $\sigma_{\chi n}$,
for dark mediators with lifetime of order ${\cal O}(0.1-1)$s. The results show
that data from Jupiter missions already probe regions in the parameter space
un- or under-explored by existing DM searches, e.g., constrain $\sigma_{\chi
n}$ of order $(10^{-40} - 10^{-38})$ cm$^2$ for 1 GeV DM dominantly
annihilating into $e^+e^-$ through dark mediators. This study serves as an
example and an initial step to explore the full physics potential of the large
planetary datasets from Jupiter missions. We also outline several other
potential directions related to secondary products of electrons, positron
signals and solar axions.
- Limits on the cosmic neutrino background
2207.12413 [abs] [pdf]
[abstract]
by Martin Bauer and Jack D. Shergold.
We present the first comprehensive discussion of constraints on the cosmic
neutrino background (C$\nu$B) overdensity, including theoretical, experimental
and cosmological limits for a wide range of neutrino masses and temperatures.
Additionally, we calculate the sensitivities of future direct and indirect
relic neutrino detection experiments and compare the results with the existing
constraints, extending several previous analyses by taking into account that
the C$\nu$B reference frame may not be aligned with that of the Earth. The
Pauli exclusion principle strongly disfavours overdensities $\eta_\nu \gg 1$ at
small neutrino masses, but allows for overdensities $\eta_{\nu}\lesssim 125$ at
the KATRIN mass bound $m_{\nu} \simeq 0.8\,\mathrm{eV}$. On the other hand,
cosmology strongly favours $0.2 \lesssim \eta_{\nu} \lesssim 3.5$ in all
scenarios. We find that direct detection proposals are capable of observing the
C$\nu$B without a significant overdensity for neutrino masses $m_{\nu} \gtrsim
50\,\mathrm{meV}$, but require an overdensity $\eta_{\nu} \gtrsim 3\times 10^5$
outside of this range. We also demonstrate that relic neutrino detection
proposals are sensitive to the helicity composition of the C$\nu$B, whilst some
may be able to distinguish between Dirac and Majorana neutrinos.
- Dark Matter Constraints from the Eccentric Supermassive Black Hole
Binary OJ 287
2207.10021 [abs] [pdf]
[abstract]
by Ahmad Alachkar, John Ellis, and Malcolm Fairbairn.
OJ 287 is a blazar thought to be a binary system containing a ~ 18 billion
solar mass primary black hole accompanied by a ~ 150 million solar mass
secondary black hole in an eccentric orbit, which triggers electromagnetic
flares twice in every ~ 12 year orbital period when it traverses the accretion
disk of the primary. The times of these emissions are consistent with the
predictions of general relativity calculated to the 4.5th post-Newtonian order.
The orbit of the secondary black hole samples the gravitational field at
distances between O(10) and O(50) Schwarzschild radii around the primary, and
hence is sensitive to the possible presence of a dark matter spike around it.
We find that the agreement of general-relativistic calculations with the
measured timings of flares from OJ 287 constrains the mass of such a spike to <
3% of the primary mass.
- Do Pulsar and Fast Radio Burst dispersion measures obey Benford's law?
2207.09696 [abs] [pdf]
[abstract]
by Pragna Mamidipaka and Shantanu Desai.
We check if the first significant digit of the dispersion measure of pulsars
and Fast Radio Bursts (using the CHIME catalog) is consistent with the Benford
distribution. We find a large disagreement with Benford's law with $\chi^2$
close to 80 for 8 degrees of freedom for both these aforementioned datasets.
This corresponds to a discrepancy of about 7$\sigma$. Therefore, we conclude
that the dispersion measures of pulsars and FRBs do not obey Benford's law.
- Diffuse supernova neutrino background
2207.09632 [abs] [pdf]
[abstract]
by Anna M. Suliga.
Neutrinos are the second most ubiquitous Standard Model particles in the
universe. On the other hand, they are also the ones least likely to interact.
Connecting these two points suggests that when a neutrino is detected, it can
divulge unique pieces of information about its source. Among the known neutrino
sources, core-collapse supernovae in the universe are the most abundant for
MeV-energies. On average, a single collapse happens every second in the
observable universe and produces $10^{58}$ neutrinos. The flux of neutrinos
reaching the Earth from all the core-collapse supernovae in the universe is
known as diffuse supernova neutrino background. In this Chapter, the basic
prediction for the diffuse supernova neutrino background is presented. This
includes a discussion of an average neutrino signal from a core-collapse
supernova, variability of that signal due to the remnant formed in the process,
and uncertainties connected to the other astrophysical parameters determining
the diffuse flux, such as cosmological supernova rate. In addition, the current
experimental limits and detection perspectives of diffuse supernova neutrino
background are reported.
- Massive neutrino self-interactions and inflation
2207.07142 [abs] [pdf]
[abstract]
by Shouvik Roy Choudhury, Steen Hannestad, and Thomas Tram.
Certain inflationary models like Natural inflation (NI) and Coleman-Weinberg
inflation (CWI) are disfavoured by cosmological data in the standard
$\Lambda\textrm{CDM}+r$ model (where $r$ is the scalar-to-tensor ratio), as
these inflationary models predict the regions in the $n_s-r$ parameter space
that are excluded by the cosmological data at more than 2$\sigma$ (here $n_s$
is the scalar spectral index). The same is true for single field inflationary
models with an inflection point that can account for all or majority of dark
matter in the form of PBHs (primordial black holes). Cosmological models
incorporating strongly self-interacting neutrinos (with a heavy mediator) are,
however, known to prefer lower $n_s$ values compared to the $\Lambda\rm CDM$
model. Considering such neutrino self-interactions can, thus, open up the
parameter space to accommodate the above inflationary models. In this work, we
implement the massive neutrino self-interactions with a heavy mediator in two
different ways: flavour-universal (among all three neutrinos), and
flavour-specific (involving only one neutrino species). We implement the new
interaction in both scalar and tensor perturbation equations of neutrinos.
Interestingly, we find that the current cosmological data can support the
aforementioned inflationary models at 2$\sigma$ in the presence of such
neutrino self-interactions.
- Model marginalized constraints on neutrino properties from cosmology
2207.05167 [abs] [pdf]
[abstract]
by Eleonora di Valentino, Stefano Gariazzo, and Olga Mena.
We present robust, model-marginalized limits on both the total neutrino mass
($\sum m_\nu$) and abundance ($N_{\rm eff}$) to minimize the role of
parameterizations, priors and models when extracting neutrino properties from
cosmology. The cosmological observations we consider are CMB temperature
fluctuation and polarization measurements, Supernovae Ia luminosity distances,
BAO observations and determinations of the growth rate parameter from the Data
Release 16 of the Sloan Digital Sky Survey IV. The degenerate neutrino mass
spectrum (which implies $\sum m_\nu>0$) is weakly (moderately) preferred over
the normal and inverted hierarchy possibilities, which imply the priors $\sum
m_\nu>0.06$ and $\sum m_\nu>0.1$ eV respectively. Concerning the underlying
cosmological model, the $\Lambda$CDM minimal scenario is almost always strongly
preferred over the possible extensions explored here. The most constraining
$95\%$ CL bound on the total neutrino mass in the $\Lambda$CDM+$\sum m_\nu$
picture is $\sum m_\nu< 0.087$ eV. The parameter $N_{\rm eff}$ is restricted to
$3.08\pm 0.17$ ($68\%$ CL) in the $\Lambda$CDM+$N_{\rm eff}$ model. These
limits barely change when considering the $\Lambda$CDM+$\sum m_\nu$+$N_{\rm
eff}$ scenario. Given the robustness and the strong constraining power of the
cosmological measurements employed here, the model-marginalized posteriors
obtained considering a large spectra of non-minimal cosmologies are very close
to the previous bounds, obtained within the $\Lambda$CDM framework in the
degenerate neutrino mass spectrum. Future cosmological measurements may improve
the current Bayesian evidence favouring the degenerate neutrino mass spectra,
challenging therefore the consistency between cosmological neutrino mass bounds
and oscillation neutrino measurements, and potentially suggesting a more
complicated cosmological model and/or neutrino sector.
- Chern-Simons Gravity and Neutrino Self-Interactions
2207.05094 [abs] [pdf]
[abstract]
by Stephon Alexander and Cyril Creque-Sarbinowski.
Dynamical Chern-Simons gravity (dCS) is a four-dimensional parity-violating
extension of general relativity. Current models predict the effect of this
extension to be negligible due to large decay constants $f$ close to the scale
of grand unified theories. Here, we present a construction of dCS allowing for
much smaller decay constants, ranging from sub-eV to Planck scales.
Specifically, we show that if there exists a fermion species with strong
self-interactions, the short-wavelength fermion modes form a bound state. This
bound state can then undergo dynamical symmetry breaking and the resulting
pseudoscalar develops Yukawa interactions with the remaining long-wavelength
fermion modes. Due to this new interaction, loop corrections with gravitons
then realize a linear coupling between the pseudoscalar and the gravitational
Chern-Simons term. The strength of this coupling is set by the Yukawa coupling
constant divided by the fermion mass. Therefore, since self-interacting
fermions with small masses are ideal, we identify neutrinos as promising
candidates. For example, if a neutrino has a mass $m_\nu \lesssim {\rm meV}$
and the Yukawa coupling is order unity, the dCS decay constant can be as small
as $f \sim 10^3 m_\nu \lesssim {\rm eV}$. We discuss other potential choices
for fermions.
- Search for Astrophysical Neutrinos from 1FLE Blazars with IceCube
2207.04946 [abs] [pdf]
[abstract]
by R. Abbasi, [and 382 more]M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, J. M. Alameddine, A. A. Alves Jr., N. M. Amin, K. Andeen, T. Anderson, G. Anton, C. Argüelles, Y. Ashida, S. Athanasiadou, S. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, V. Basu, R. Bay, J. J. Beatty, K. -H. Becker, J. Becker Tjus, J. Beise, C. Bellenghi, S. Benda, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, G. Binder, D. Bindig, E. Blaufuss, S. Blot, F. Bontempo, J. Y. Book, J. Borowka, S. Böser, O. Botner, J. Böttcher, E. Bourbeau, F. Bradascio, J. Braun, B. Brinson, S. Bron, J. Brostean-Kaiser, R. T. Burley, R. S. Busse, M. A. Campana, E. G. Carnie-Bronca, C. Chen, Z. Chen, D. Chirkin, K. Choi, B. A. Clark, L. Classen, A. Coleman, G. H. Collin, A. Connolly, J. M. Conrad, P. Coppin, P. Correa, D. F. Cowen, R. Cross, C. Dappen, P. Dave, C. De Clercq, J. J. DeLaunay, D. Delgado López, H. Dembinski, K. Deoskar, A. Desai, P. Desiati, K. D. de Vries, G. de Wasseige, T. DeYoung, A. Diaz, J. C. Díaz-Vélez, M. Dittmer, H. Dujmovic, M. A. DuVernois, T. Ehrhardt, P. Eller, R. Engel, H. Erpenbeck, J. Evans, P. A. Evenson, K. L. Fan, A. R. Fazely, A. Fedynitch, N. Feigl, S. Fiedlschuster, A. T. Fienberg, C. Finley, L. Fischer, D. Fox, A. Franckowiak, E. Friedman, A. Fritz, P. Fürst, T. K. Gaisser, J. Gallagher, E. Ganster, A. Garcia, S. Garrappa, L. Gerhardt, A. Ghadimi, C. Glaser, T. Glauch, T. Glüsenkamp, N. Goehlke, J. G. Gonzalez, S. Goswami, D. Grant, T. Grégoire, S. Griswold, C. Günther, P. Gutjahr, C. Haack, A. Hallgren, R. Halliday, L. Halve, F. Halzen, H. Hamdaoui, M. Ha Minh, K. Hanson, J. Hardin, A. A. Harnisch, P. Hatch, A. Haungs, K. Helbing, J. Hellrung, F. Henningsen, E. C. Hettinger, L. Heuermann, S. Hickford, J. Hignight, C. Hill, G. C. Hill, K. D. Hoffman, K. Hoshina, W. Hou, M. Huber, T. Huber, K. Hultqvist, M. Hünnefeld, R. Hussain, K. Hymon, S. In, N. Iovine, A. Ishihara, M. Jansson, G. S. Japaridze, M. Jeong, M. Jin, B. J. P. Jones, D. Kang, W. Kang, X. Kang, A. Kappes, D. Kappesser, L. Kardum, T. Karg, M. Karl, A. Karle, U. Katz, M. Kauer, J. L. Kelley, A. Kheirandish, K. Kin, J. Kiryluk, S. R. Klein, A. Kochocki, R. Koirala, H. Kolanoski, T. Kontrimas, L. Köpke, C. Kopper, S. Kopper, D. J. Koskinen, P. Koundal, M. Kovacevich, M. Kowalski, T. Kozynets, E. Krupczak, E. Kun, N. Kurahashi, N. Lad, C. Lagunas Gualda, M. J. Larson, F. Lauber, J. P. Lazar, J. W. Lee, K. Leonard, A. Leszczyńska, M. Lincetto, Q. R. Liu, M. Liubarska, E. Lohfink, C. J. Lozano Mariscal, L. Lu, F. Lucarelli, A. Ludwig, W. Luszczak, Y. Lyu, W. Y. Ma, J. Madsen, K. B. M. Mahn, Y. Makino, S. Mancina, W. Marie Sainte, I. C. Mariş, I. Martinez-Soler, R. Maruyama, S. McCarthy, T. McElroy, F. McNally, J. V. Mead, K. Meagher, S. Mechbal, A. Medina, M. Meier, S. Meighen-Berger, Y. Merckx, J. Micallef, D. Mockler, T. Montaruli, R. W. Moore, R. Morse, M. Moulai, T. Mukherjee, R. Naab, R. Nagai, U. Naumann, J. Necker, L. V. Nguyen, H. Niederhausen, M. U. Nisa, S. C. Nowicki, A. Obertacke Pollmann, M. Oehler, B. Oeyen, A. Olivas, J. Osborn, E. O'Sullivan, H. Pandya, D. V. Pankova, N. Park, G. K. Parker, E. N. Paudel, L. Paul, C. Pérez de los Heros, L. Peters, J. Peterson, S. Philippen, S. Pieper, A. Pizzuto, M. Plum, Y. Popovych, A. Porcelli, M. Prado Rodriguez, B. Pries, G. T. Przybylski, C. Raab, J. Rack-Helleis, A. Raissi, M. Rameez, K. Rawlins, I. C. Rea, Z. Rechav, A. Rehman, P. Reichherzer, G. Renzi, E. Resconi, S. Reusch, W. Rhode, M. Richman, B. Riedel, E. J. Roberts, S. Robertson, S. Rodan, G. Roellinghoff, M. Rongen, C. Rott, T. Ruhe, D. Ryckbosch, D. Rysewyk Cantu, I. Safa, J. Saffer, D. Salazar-Gallegos, P. Sampathkumar, S. E. Sanchez Herrera, A. Sandrock, M. Santander, S. Sarkar, S. Sarkar, K. Satalecka, M. Schaufel, H. Schieler, S. Schindler, T. Schmidt, A. Schneider, J. Schneider, F. G. Schröder, L. Schumacher, G. Schwefer, S. Sclafani, D. Seckel, S. Seunarine, A. Sharma, S. Shefali, N. Shimizu, M. Silva, B. Skrzypek, B. Smithers, R. Snihur, J. Soedingrekso, A. Sogaard, D. Soldin, C. Spannfellner, G. M. Spiczak, C. Spiering, M. Stamatikos, T. Stanev, R. Stein, J. Stettner, T. Stezelberger, T. Stürwald, T. Stuttard, G. W. Sullivan, I. Taboada, S. Ter-Antonyan, W. G. Thompson, J. Thwaites, S. Tilav, K. Tollefson, C. Tönnis, S. Toscano, D. Tosi, A. Trettin, M. Tselengidou, C. F. Tung, A. Turcati, R. Turcotte, J. P. Twagirayezu, B. Ty, M. A. Unland Elorrieta, M. Unland Elorrieta, K. Upshaw, N. Valtonen-Mattila, J. Vandenbroucke, N. van Eijndhoven, D. Vannerom, J. van Santen, J. Veitch-Michaelis, S. Verpoest, C. Walck, W. Wang, T. B. Watson, C. Weaver, P. Weigel, A. Weindl, J. Weldert, C. Wendt, J. Werthebach, M. Weyrauch, N. Whitehorn, C. H. Wiebusch, N. Willey, D. R. Williams, M. Wolf, G. Wrede, J. Wulff, X. W. Xu, J. P. Yanez, E. Yildizci, S. Yoshida, S. Yu, T. Yuan, Z. Zhang, and P. Zhelnin [hide authors].
The majority of astrophysical neutrinos have undetermined origins. The
IceCube Neutrino Observatory has observed astrophysical neutrinos but has not
yet identified their sources. Blazars are promising source candidates, but
previous searches for neutrino emission from populations of blazars detected in
$\gtrsim$ GeV gamma-rays have not observed any significant neutrino excess.
Recent findings in multi-messenger astronomy indicate that high-energy photons,
co-produced with high-energy neutrinos, are likely to be absorbed and reemitted
at lower energies. Thus, lower-energy photons may be better indicators of
TeV-PeV neutrino production. This paper presents the first time-integrated
stacking search for astrophysical neutrino emission from MeV-detected blazars
in the first Fermi-LAT low energy catalog (1FLE) using ten years of IceCube
muon-neutrino data. The results of this analysis are found to be consistent
with a background-only hypothesis. Assuming an E$^{-2}$ neutrino spectrum and
proportionality between the blazars' MeV gamma-ray fluxes and TeV-PeV neutrino
flux, the upper limit on the 1FLE blazar energy-scaled neutrino flux is
determined to be $1.64 \times 10^{-12}$ TeV cm$^{-2}$ s$^{-1}$ at 90%
confidence level. This upper limit is approximately 1% of IceCube's diffuse
muon-neutrino flux measurement.
- A First Search for Solar $^8$B Neutrino in the PandaX-4T Experiment
using Neutrino-Nucleus Coherent Scattering
2207.04883 [abs] [pdf]
[abstract]
by Wenbo Ma, [and 90 more]Abdusalam Abdukerim, Chen Cheng, Zihao Bo, Wei Chen, Xun Chen, Yunhua Chen, Zhaokan Cheng, Xiangyi Cui, Yingjie Fan, Deqing Fang, Changbo Fu, Mengting Fu, Lisheng Geng, Karl Giboni, Linhui Gu, Xuyuan Guo, Chencheng Han, Ke Han, Changda He, Jinrong He, Di Huang, Yanlin Huang, Zhou Huang, Ruquan Hou, Xiangdong Ji, Yonglin Ju, Chenxiang Li, Jiafu Li, Mingchuan Li, Shu Li, Shuaijie Li, Qing Lin, Jianglai Liu, Xiaoying Lu, Lingyin Luo, Yunyang Luo, Yugang Ma, Yajun Mao, Nasir Shaheed, Yue Meng, Xuyang Ning, Ningchun Qi, Zhicheng Qian, Xiangxiang Ren, Changsong Shang, Xiaofeng Shang, Guofang Shen, Lin Si, Wenliang Sun, Andi Tan, Yi Tao, Anqing Wang, Meng Wang, Qiuhong Wang, Shaobo Wang, Siguang Wang, Wei Wang, Xiuli Wang, Zhou Wang, Yuehuan Wei, Mengmeng Wu, Weihao Wu, Jingkai Xia, Mengjiao Xiao, Xiang Xiao, Pengwei Xie, Binbin Yan, Xiyu Yan, Jijun Yang, Yong Yang, Chunxu Yu, Jumin Yuan, Ying Yuan, Zhe Yuan, Xinning Zeng, Dan Zhang, Minzhen Zhang, Peng Zhang, Shibo Zhang, Shu Zhang, Tao Zhang, Yingxin Zhang, Yuanyuan Zhang, Li Zhao, Qibin Zheng, Jifang Zhou, Ning Zhou, Xiaopeng Zhou, Yong Zhou, and Yubo Zhou [hide authors].
A search for interactions from solar $^8$B neutrinos elastically scattering
off xenon nuclei using PandaX-4T commissioning data is reported. The energy
threshold of this search is further lowered compared with the previous search
for dark matter, with various techniques utilized to suppress the background
that emerges from data with the lowered threshold. A blind analysis is
performed on the data with an effective exposure of 0.48 tonne$\cdot$year, and
no significant excess of events is observed. Among results obtained using the
neutrino-nucleus coherent scattering, our results give the best constraint on
the solar $^8$B neutrino flux. We further provide a more stringent limit on the
cross section between dark matter and nucleon in the mass range from 3 to 9
GeV/c$^2$.
- Neutrino Mass Ordering -- Circumventing the Challenges using Synergy
between T2HK and JUNO
2207.04784 [abs] [pdf]
[abstract]
by Sandhya Choubey, Monojit Ghosh, and Deepak Raikwal.
One of the major open problems of neutrino physics is MO (mass ordering). We
discuss the prospects of measuring MO with two under-construction experiments
T2HK and JUNO. JUNO alone is expected to measure MO with greater than $3\sigma$
significance as long as certain experimental challenges are met. In particular,
JUNO needs better than 3$\%$ energy resolution for MO measurement. On the other
hand, T2HK has rather poor prospects at measuring the MO, especially for
certain ranges of the CP violating parameter $\delta_{\rm CP}$, posing a major
drawback for T2HK. In this letter we show that the synergy between JUNO and
T2HK will bring two-fold advantage. Firstly, the synergy between the two
experiments helps us determine the MO at a very high significance. With the
baseline set-up of the two experiments, we have a greater than $9\sigma$
determination of the MO for all values of $\delta_{\rm CP}$. Secondly, the
synergy also allows us to relax the constraints on the two experiments. We show
that JUNO, could perform extremely well even for energy resolution of 5$\%$,
while for T2HK the MO problem with "bad" values of $\delta_{\rm CP}$ goes away.
The MO sensitivity for the combined analysis is expected to be greater than
$6\sigma$ for all values of $\delta_{\rm CP}$ and with just 5$\%$ energy
resolution for JUNO.
- Solar $\barν_e$ flux: Revisiting bounds on neutrino magnetic moments
and solar magnetic field
2207.04516 [abs] [pdf]
[abstract]
by Evgeny Akhmedov and Pablo Martínez-Miravé.
The interaction of neutrino transition magnetic dipole moments with magnetic
fields can give rise to the phenomenon of neutrino spin-flavour precession
(SFP). For Majorana neutrinos, the combined action of SFP of solar neutrinos
and flavour oscillations would manifest itself as a small, yet potentially
detectable, flux of electron antineutrinos coming from the Sun. Non-observation
of such a flux constrains the product of the neutrino magnetic moment $\mu$ and
the strength of the solar magnetic field $B$. We derive a simple analytical
expression for the expected $\bar{\nu}_e$ appearance probability in the
three-flavour framework and we use it to revisit the existing experimental
bounds on $\mu B$. A full numerical calculation has also been performed to
check the validity of the analytical result. We also present our numerical
results in energy-binned form, convenient for analyses of the data of the
current and future experiments searching for the solar $\bar{\nu}_e$ flux. In
addition, we give a comprehensive compilation of other existing limits on
neutrino magnetic moments and of the expressions for the probed effective
magnetic moments in terms of the fundamental neutrino magnetic moments and
leptonic mixing parameters.
- Predicting leptonic CP violation via minimization of neutrino
entanglement
2207.03303 [abs] [pdf]
[abstract]
by Gonçalo M. Quinta, Alexandre Sousa, and Yasser Omar.
We show how a minimization principle of quantum entanglement between the
oscillating flavors of a neutrino leads to a unique prediction for the
CP-violation phase in the neutrino sector without assuming extra symmetries in
the Standard Model. We find a theoretical prediction consistent with either no
CP-violation or a very small presence of it.
- Study of matter effects in the presence of sterile neutrino using OMSD
approximation
2207.03249 [abs] [pdf]
[abstract]
by Kiran Sharma and Sudhanwa Patra.
We discuss the transition and survival probabilities in $3+1$ neutrino flavor
mixing scenario in presence of matter effects. We adopt the well-known OMSD(One
Mass Scale Dominance) approximation to carry out our analysis. After that we
perform series expansion about $\sin \theta_{13}$ term upto second order. We
find that our results are consistent with the already existing $\alpha - \sin
\theta_{13}$ approximated relations in the limit of vanishing $\alpha$ and
phases involving sterile neutrinos. We also figure out that survival transition
probability becomes independent of the fundamental and sterile CP phases under
our formalism. Hence, it provides us a new way to look at only matter effects
contribution to oscillation probability. Also, the transition probability at
the same time gives an independent study of CP-violation arising from the
sterile phases, in the vicinity of fundamental CP violation phase. We provide
the relation for the atmospheric probability in the presence of matter by
performing the series expansion upto linear order about parameter $A (= 2EV)$,
with V being the effective matter potential under OMSD approximation.
- Imprints of flavor anomalies on neutrino oscillations through dark
matter halo
2207.02962 [abs] [pdf]
[abstract]
by Ashutosh Kumar Alok, Neetu Raj Singh Chundawat, and Arindam Mandal.
In this work we study the impact of new physics, stimulated by flavor
anomalies, on neutrino oscillations through dense dark matter halo. Inspired by
a model where a Majorana dark matter fermion and two new scalar fields
contribute to $b \to s \mu^+ \mu^-$ transition at the one loop level, we study
the impact of neutrino-dark matter interaction on the oscillation patterns of
ultra-high energy cosmic neutrinos passing through this muonphilic halo located
near the center of Milky Way. We find that due to this interaction, the flavor
ratios of neutrinos reaching earth would be different from that of vacuum
oscillations. We also consider a $Z'$ model driven by $L_{\mu}-L_{\tau}$
symmetry and containing a vector-like fermion as a dark matter candidate. It
was previously shown that for such a model, the three flavors of neutrinos
decouple from each other. This will render a flavor ratio similar to that of
vacuum oscillations. Therefore, the interaction of neutrinos with dense dark
matter halo can serve as an important tool to discriminate between flavor
models with a dark connection.
- A New Probe of Relic Neutrino Clustering using Cosmogenic Neutrinos
2207.02860 [abs] [pdf]
[abstract]
by Vedran Brdar, [and 3 more]P. S. Bhupal Dev, Ryan Plestid, and Amarjit Soni [hide authors].
We propose a new probe of cosmic relic neutrinos (C$\nu$B) using their
resonant scattering against cosmogenic neutrinos. Depending on the lightest
neutrino mass and the energy spectrum of the cosmogenic neutrino flux, a
Standard Model vector meson (such as a hadronic $\rho$) resonance can be
produced via $\nu\bar{\nu}$ annihilation. This leads to a distinct absorption
feature in the cosmogenic neutrino flux at an energy solely determined by the
meson mass and the neutrino mass, apart from redshift. By numerical
coincidence, the position of the $\rho$-resonance overlaps with the originally
predicted peak of the Greisen-Zatsepin-Kuzmin (GZK) neutrino flux, which offers
an enhanced absorption effect at higher redshifts. We show that this absorption
feature in the GZK neutrino flux may be observable in future radio-based
neutrino observatories, such as IceCube-Gen2 radio, provided there exists a
large overdensity in the C$\nu$B distribution. This therefore provides a new
probe of C$\nu$B clustering at large redshifts, complementary to the laboratory
probes (such as KATRIN) at zero redshift.
- Large Extra Dimensions and neutrino experiments
2207.02790 [abs] [pdf]
[abstract]
by D. V. Forero, [and 3 more]C. Giunti, C. A. Ternes, and O. Tyagi [hide authors].
The existence of Large Extra Dimensions can be probed in various neutrino
experiments. We analyze several neutrino data sets in a model with a dominant
large extra dimension. We show that the Gallium anomaly can be explained with
neutrino oscillations induced by the large extra dimension, but the region of
parameter space which is preferred by the Gallium anomaly is in tension with
the bounds from reactor rate data, as well as the data of Daya Bay and MINOS.
We also present bounds obtained from the analysis of the KATRIN data. We show,
that current experiments can put strong bounds on the size $R_{\text{ED}}$ of
the extra dimension: $R_{\text{ED}} < 0.20~\mu\text{m}$ and $R_{\text{ED}} <
0.10~\mu\text{m}$ at 90\% C.L. for normal and inverted ordering of the standard
neutrino masses, respectively.
- Baseline and other effects for a sterile neutrino at DUNE
2207.02331 [abs] [pdf]
[abstract]
by J. T. Penedo and João Pulido.
We analyze the sensitivity of the Deep Underground Neutrino Experiment (DUNE)
to a sterile neutrino, combining information from both near and far detectors.
We quantify often-neglected effects which may impact the event rate estimation
in a 3+1 oscillation scenario. In particular, we find that taking into account
the information on the neutrino production point, in contrast to assuming a
pointlike neutrino source, affects DUNE's sterile exclusion reach. Visible
differences remain after the inclusion of energy bin-to-bin uncorrelated
systematics. Instead, implementing exact oscillation formulae for near detector
events, including a two slab density profile, does not result in any visible
change in the sensitivity.
- Double and multiple bangs at tau neutrino telescopes: A novel probe of
sphalerons with cosmogenic neutrinos
2207.02222 [abs] [pdf]
[abstract]
by Guo-yuan Huang.
In light of the exciting campaign of cosmogenic neutrino detection, we
investigate the double and multiple tau bangs detectable at future tau neutrino
telescopes. Such events are expected from the Standard Model (SM) higher-order
processes, which can be easily identified with broad techniques anticipated at
future tau neutrino telescopes. We find that SM perturbative processes can
already contribute observable double-bang events to telescopes with a
sensitivity of collecting $\mathcal{O}(100)$ cosmogenic neutrino events. The
detectable but suppressed rate in fact makes the double and multiple bangs an
excellent probe of SM unknowns and possible new physics beyond. As a case
study, the nonperturbative sphaleron process, which can copiously produce
multiple tau bangs, is explored.
- Updated neutrino mass constraints from galaxy clustering and CMB
lensing-galaxy cross-correlation measurements
2207.01913 [abs] [pdf]
[abstract]
by Isabelle Tanseri, [and 4 more]Steffen Hagstotz, Sunny Vagnozzi, Elena Giusarma, and Katherine Freese [hide authors].
We revisit cosmological constraints on the sum of the neutrino masses $\Sigma
m_\nu$ from a combination of full-shape BOSS galaxy clustering [$P(k)$] data
and measurements of the cross-correlation between Planck Cosmic Microwave
Background (CMB) lensing convergence and BOSS galaxy overdensity maps
[$C^{\kappa \text{g}}_{\ell}$], using a simple but theoretically motivated
model for the scale-dependent galaxy bias in auto- and cross-correlation
measurements. We improve upon earlier related work in several respects,
particularly through a more accurate treatment of the correlation and
covariance between $P(k)$ and $C^{\kappa \text{g}}_{\ell}$ measurements. When
combining these measurements with Planck CMB data, we find a 95% confidence
level upper limit of $\Sigma m_\nu<0.14\,{\rm eV}$, while slightly weaker
limits are obtained when including small-scale ACTPol CMB data, in agreement
with our expectations. We confirm earlier findings that (once combined with CMB
data) the full-shape information content is comparable to the geometrical
information content in the reconstructed BAO peaks given the precision of
current galaxy clustering data, discuss the physical significance of our
inferred bias and shot noise parameters, and perform a number of robustness
tests on our underlying model. While the inclusion of $C^{\kappa
\text{g}}_{\ell}$ measurements does not currently appear to lead to substantial
improvements in the resulting $\Sigma m_{\nu}$ constraints, we expect the
converse to be true for near-future galaxy clustering measurements, whose shape
information content will eventually supersede the geometrical one.
June 2022
- Dark photon superradiance quenched by dark matter
2206.12367 [abs] [pdf]
[abstract]
by Enrico Cannizzaro, [and 3 more]Laura Sberna, Andrea Caputo, and Paolo Pani [hide authors].
Black-hole superradiance has been used to place very strong bounds on a
variety of models of ultralight bosons such as axions, new light scalars, and
dark photons. It is common lore to believe that superradiance bounds are
broadly model independent and therefore pretty robust. In this work we show
however that superradiance bounds on dark photons can be challenged by simple,
compelling extensions of the minimal model. In particular, if the dark photon
populates a larger dark sector and couples to dark fermions playing the role of
dark matter, then superradiance bounds can easily be circumvented, depending on
the mass and (dark) charge of the dark matter.
- Extracting the best physics sensitivity from T2HKK: A study on optimal
detector volume
2206.10320 [abs] [pdf]
[abstract]
by Papia Panda, [and 3 more]Monojit Ghosh, Priya Mishra, and Rukmani Mohanta [hide authors].
T2HK is an upcoming long-baseline experiment in Japan which will have two
water Cherenkov detector tanks of 187 kt volume each at distance of 295 km from
the source. An alternative project, T2HKK is also under consideration where one
of the water tanks will be moved to Korea at a distance of 1100 km. The flux at
295 km will cover the first oscillation maximum and the flux at 1100 km will
mainly cover the second oscillation maximum. As physics sensitivity at the dual
baseline rely on variation in statistics, dependence of systematic uncertainty,
effect of second oscillation maximum and matter density, 187 kt detector volume
at 295 km and 187 kt detector volume at 1100 km may not be the optimal
configuration of T2HKK. Therefore, we have tried to optimize the ratio of the
detector volume at both the locations by studying the interplay between the
above mentioned parameters. For the analysis of neutrino mass hierarchy, octant
of $\theta_{23}$ and CP precision, we have considered two values of
$\delta_{\rm{CP}}$ as 270$^\circ$ and $0^\circ$ and for CP violation we have
considered the value of $\delta_{\rm CP}= 270^\circ$. These values are
motivated by the current best-fit values of this parameter as obtained from the
experiments T2K and NO$\nu$A. Interestingly we find that if the systematic
uncertainty is negligible then the T2HK setup i.e., when both the detector
tanks are placed at 295 km gives the best results in terms of hierarchy
sensitivity at $\delta_{\rm CP}= 270^\circ$, octant sensitivity, CP violation
sensitivity and CP precision sensitivity at $\delta_{\rm CP}= 0^\circ$. For
current values of systematic errors, we find that neither T2HK, nor T2HKK setup
is giving better results for hierarchy, CP violation and CP precision
sensitivity. The optimal detector volume which is of the range between 255 kt
to 345 kt at 1100 km gives better results in those above mentioned parameters.
- Probing non-standard neutrino interactions with a light boson from next
galactic and diffuse supernova neutrinos
2206.06852 [abs] [pdf]
[abstract]
by Kensuke Akita, Sang Hui Im, and Mehedi Masud.
Non-standard neutrino interactions with a massive boson can produce the
bosons in the core of core-collapse supernovae (SNe). After the emission of the
bosons from the SN core, their subsequent decays into neutrinos can modify the
SN neutrino flux. We show future observations of neutrinos from a next galactic
SN in Super-Kamiokande (SK) and Hyper-Kamiokande (HK) can probe
flavor-universal non-standard neutrino couplings to a light boson, improving
the previous limit from the SN 1987A neutrino burst by several orders of
magnitude. We also discuss sensitivity of the flavor-universal non-standard
neutrino interactions in future observations of diffuse neutrinos from all the
past SNe, known as the diffuse supernova neutrino background (DSNB). According
to our analysis, observations of the DSNB in HK, JUNO and DUNE experiments can
probe such couplings by a factor of $\sim 2$ beyond the SN 1987A constraint.
However, our result is also subject to a large uncertainty concerning the
precise estimation of the DSNB.
- Symmetry in neutrino oscillation in matter with non-unitarity
2206.06474 [abs] [pdf]
[abstract]
by Hisakazu Minakata.
Recently we have developed a method called ``Symmetry Finder'' (SF) for
hunting the reparametrization symmetry in the three-neutrino system in matter.
Here, we apply SF to the Denton {\it et al.} (DMP) perturbation theory extended
by including unitarity violation (UV), a possible low-energy manifestation of
physics beyond the $\nu$SM. Implementation of UV into the SF framework yields
the additional two very different constraints, which nonetheless allow
remarkably consistent solutions, the eight DMP-UV symmetries. Treatment of one
of the constraints, the genuine non-unitary part, leads to the key identity
which entails the UV $\alpha$ parameter transformation only by rephasing, which
innovates the invariance proof of the Hamiltonian. The quantum mechanical
nature of the symmetry dictates the both $\nu$SM and UV variables to transform
jointly, through which the response of the two sectors are related to reveal
their interplay. Thus, the symmetry can serve for a tool for diagnostics,
probing the interrelation between the $\nu$SM and a low-energy description of
new physics. Problem of SF symmetry in vacuum is revisited to complete eight
symmetries akin to DMP's.
- High-Energy Astrophysical Neutrinos from Cosmic Strings
2206.06377 [abs] [pdf]
[abstract]
by Cyril Creque-Sarbinowski, Jeffrey Hyde, and Marc Kamionkowski.
Cosmic strings that couple to neutrinos may account for a portion of the
high-energy astrophysical neutrino (HEAN) flux seen by IceCube. Here, we
calculate the observed spectrum of neutrinos emitted from a population of
cosmic string loops that contain quasi-cusps, -kinks, or kink-kink collisions.
We consider two broad neutrino emission models: one where these string features
emit a neutrino directly, and one where they emit a scalar particle which then
eventually decays to a neutrino. In either case, the spectrum of cosmic string
neutrinos does not match that of the observed HEAN spectrum. We thus find that
the maximum contribution of cosmic string neutrinos, through these two
scenarios, to be at most $\sim 45$ % of the observed flux. However, we also
find that the presence of cosmic string neutrinos can lead to bumps in the
observed neutrino spectrum. Finally, for each of the models presented, we
present the viable parameter space for neutrino emission.
- Impact of late-time neutrino emission on the diffuse supernova neutrino
background
2206.05299 [abs] [pdf]
[abstract]
by Nick Ekanger, [and 3 more]Shunsaku Horiuchi, Kei Kotake, and Kohsuke Sumiyoshi [hide authors].
In the absence of high-statistics supernova neutrino measurements, estimates
of the diffuse supernova neutrino background (DSNB) hinge on the precision of
simulations of core-collapse supernovae. Understanding the cooling phase of
protoneutron star (PNS) evolution ($\gtrsim1\,{\rm s}$ after core bounce) is
crucial, since approximately 50% of the energy liberated by neutrinos is
emitted during the cooling phase. We model the cooling phase with a hybrid
method by combining the neutrino emission predicted by 3D hydrodynamic
simulations with several cooling-phase estimates, including a novel
two-parameter correlation depending on the final baryonic PNS mass and the time
of shock revival. We find that the predicted DSNB event rate at
Super-Kamiokande can vary by a factor of $\sim2-3$ depending on the
cooling-phase treatment. We also find that except for one cooling estimate, the
range in predicted DSNB events is largely driven by the uncertainty in the
neutrino mean energy. With a good understanding of the late-time neutrino
emission, more precise DSNB estimates can be made for the next generation of
DSNB searches.
- Energizing gamma ray bursts via $Z^\prime$ mediated neutrino heating
2206.03485 [abs] [pdf]
[abstract]
by Tanmay Kumar Poddar, Srubabati Goswami, and Arvind Kumar Mishra.
The pair annihilation of neutrinos $(\nu\overline{\nu}\rightarrow e^+e^-)$
can energize violent stellar explosions such as gamma ray bursts (GRBs). The
energy in this neutrino heating mechanism can be further enhanced by modifying
the background spacetime over that of Newtonian spacetime. However, one cannot
attain the maximum GRB energy $(\sim 10^{52}~\rm{erg})$ in either the Newtonian
background or Schwarzschild and Hartle-Thorne background. On the other hand,
using modified gravity theories or the Quintessence field as background
geometries, the maximum GRB energy can be reached. In this paper, we consider
extending the standard model by an extra $U(1)_{\rm{B-L}}$ gauge group and
augmenting the energy deposition by neutrino pair annihilation process
including contributions mediated by the $Z^\prime$ gauge boson belonging to
this model. From the observed energy of GRB, we obtain constraints on
$U(1)_{\rm{B-L}}$ gauge coupling in different background spacetimes. We find
that the bounds on gauge coupling in modified gravity theories and quintessence
background are stronger than those coming from the neutrino-electron scattering
experiments in the limit of small gauge boson masses. Future GRB observations
with better accuracy can further strengthen these bounds.
- Evaluations of uncertainties in simulations of propagation of
ultrahigh-energy cosmic-ray nuclei derived from microscopic nuclear models
2206.03447 [abs] [pdf]
[abstract]
by E. Kido, [and 7 more]T. Inakura, M. Kimura, N. Kobayashi, S. Nagataki, N. Shimizu, A. Tamii, and Y. Utsuno [hide authors].
Photodisintegration is a main energy loss process for ultrahigh-energy
cosmic-ray (UHECR) nuclei in intergalactic space. Therefore, it is crucial to
understand systematic uncertainty in photodisintegration when simulating the
propagation of UHECR nuclei. In this work, we calculated the cross sections
using the random phase approximation (RPA) of density functional theory (DFT),
a microscopic nuclear model. We calculated the $E1$ strength of 29 nuclei using
three different density functionals. We obtained the cross sections of
photonuclear reactions, including photodisintegration, with the $E1$ strength.
Then, we implemented the cross sections in the cosmic-ray propagation code
CRPropa. We found that assuming certain astrophysical parameter values, the
difference between UHECR energy spectrum predictions using the RPA calculation
and the default photodisintegration model in CRPropa can be more than the
statistical uncertainty of the spectrum. We also found that the differences
between the RPA calculations and CRPropa default in certain astrophysical
parameters obtained by a combined fit of UHECR energy spectrum and composition
data assuming a phenomenological model of UHECR sources can be more than the
uncertainty of the data.
- Non-Standard Interaction of atmospheric neutrino in future experiments
2206.02594 [abs] [pdf]
[abstract]
by Pouya Bakhti, Meshkat Rajaee, and Seodong Shin.
We show the prospects of probing neutral-current non-standard interaction
(NSI) in the propagation of atmospheric neutrinos in future large-volume
neutrino experiments including DUNE, HK, KNO, and ORCA. For DUNE, we utilize
its ability of identifying the tau neutrino event and combine the $\nu_\tau$
appearance with the $\nu_\mu$ disappearance. Based on our simulated results,
the ten years of data taking of the atmospheric neutrinos can enormously
improve the bounds on the NSI parameters $\varepsilon_{\mu \tau}, |
\varepsilon_{\mu \mu} - \varepsilon_{\tau \tau} |$, $\varepsilon_{e \mu }$,
$\varepsilon_{e \tau}$ and $| \varepsilon_{\mu \mu} - \varepsilon_{e e} |$ by a
couple of orders of magnitudes. In addition, we show the expected correlations
between the CP-violation phase $\delta_{CP}$ and the NSI parameters
$\varepsilon_{e\mu}, \varepsilon_{e\tau}$, and $|\varepsilon_{ee} -
\varepsilon_{\mu \mu}|$ and confirm the potentials of DUNE, HK, KNO (combined
with HK) in excluding the "No CP violation" hypothesis at 1$\sigma$, 2$\sigma$,
and 3$\sigma$, respectively.
- Concept for a Space-based Near-Solar Neutrino Detector
2206.00703 [abs] [pdf]
[abstract]
by N. Solomey, [and 10 more]J. Folkerts, H. Meyer, C. Gimar, J. Novak, B. Doty, T. English, L. Buchele, A. Nelsen, R. McTaggart, and M. Christl [hide authors].
The concept of putting a neutrino detector in close orbit of the sun has been
unexplored until very recently. The primary scientific return is to vastly
enhance our understanding of the solar interior, which is a major NASA goal.
Preliminary calculations show that such a spacecraft, if properly shielded, can
operate in space environments while taking data from neutrino interactions.
These interactions can be distinguished from random background rates of solar
electromagnetic emissions, galactic charged cosmic-rays, and gamma-rays by
using a double pulsed signature. Early simulations of this project have shown
this veto schema to be successful in eliminating background and identifying the
neutrino interaction signal in upwards of 75% of gamma ray interactions and
nearly 100% of other interactions. Hence, we propose a new instrument to
explore and study our sun. Due to inverse square scaling, this instrument has
the potential to outperform earth-based experiments in several domains such as
making measurements not accessible from the earth's orbit.
May 2022
- Abundances of uranium and thorium elements in Earth estimated by
geoneutrino spectroscopy
2205.14934 [abs] [pdf]
[abstract]
by S. Abe, [and 67 more]S. Asami, M. Eizuka, S. Futagi, A. Gando, Y. Gando, T. Gima, A. Goto, T. Hachiya, K. Hata, K. Hosokawa, K. Ichimura, S. Ieki, H. Ikeda, K. Inoue, K. Ishidoshiro, Y. Kamei, N. Kawada, Y. Kishimoto, M. Koga, M. Kurasawa, N. Maemura, T. Mitsui, H. Miyake, T. Nakahata, K. Nakamura, K. Nakamura, R. Nakamura, H. Ozaki, T. Sakai, H. Sambonsugi, I. Shimizu, Y. Shirahata, J. Shirai, K. Shiraishi, A. Suzuki, Y. Suzuki, A. Takeuchi, K. Tamae, H. Watanabe, Y. Yoshida, S. Obara, A. K. Ichikawa, S. Yoshida, S. Umehara, K. Fushimi, K. Kotera, Y. Urano, B. E. Berger, B. K. Fujikawa, J. G. Learned, J. Maricic, S. N. Axani, Z. Fu, J. Smolsky, L. A. Winslow, Y. Efremenko, H. J. Karwowski, D. M. Markoff, W. Tornow, A. Li, J. A. Detwiler, S. Enomoto, M. P. Decowski, C. Grant, H. Song, T. O'Donnell, and S. Dell'Oro [hide authors].
The decay of the primordial isotopes $^{238}\mathrm{U}$, $^{235}\mathrm{U}$,
$^{232}\mathrm{Th}$, and $^{40}\mathrm{K}$ have contributed to the terrestrial
heat budget throughout the Earth's history. Hence the individual abundance of
those isotopes are key parameters in reconstructing contemporary Earth model.
The geoneutrinos produced by the radioactive decays of uranium and thorium have
been observed with the Kamioka Liquid-Scintillator Antineutrino Detector
(KamLAND). Those measurements have been improved with more than 18-year
observation time, and improvements in detector background levels mainly by an
8-year almost rector-free period now permit spectroscopy with geoneutrinos. Our
results yield the first constraint on both uranium and thorium heat
contributions. Herein the KamLAND result is consistent with geochemical
estimations based on elemental abundances of chondritic meteorites and mantle
peridotites. The High-Q model is disfavored at 99.76% C.L. and a fully
radiogenic model is excluded at 5.2$\sigma$ assuming a homogeneous heat
producing element distribution in the mantle.
- Dark Matter Pollution in the Diffuse Supernova Neutrino Background
2205.14123 [abs] [pdf]
[abstract]
by Nicole F. Bell, Matthew J. Dolan, and Sandra Robles.
The Hyper-Kamiokande (HyperK) experiment is expected to precisely measure the
Diffuse Supernova Neutrino Background (DSNB). This requires that the
backgrounds in the relevant energy range are well understood. One possible
background that has not been considered thus far is the annihilation of
low-mass dark matter (DM) to neutrinos. We conduct simulations of the DSNB
signal and backgrounds in HyperK, and quantify the extent to which DM
annihilation products can pollute the DSNB signal. We find that the presence of
DM could affect the determination of the correct values of parameters of
interest for DSNB physics, such as effective neutrino temperatures and star
formation rates. While this opens the possibility of simultaneously
characterising the DNSB and discovering dark matter via indirect detection, we
argue that it would be hard to disentangle the two contributions due to the
lack of angular information available at low energies.
- Determination of supermassive black hole spins in local active galactic
nuclei
2205.10623 [abs] [pdf]
[abstract]
by M. Yu. Piotrovich, S. D. Buliga, and T. M. Natsvlishvili.
We estimated the radiative efficiency and spin value for a number of local
active galactic nuclei with z < 0.34 using 3 popular models connecting the
radiative efficiency with such parameters of AGNs as mass of supermassive black
hole, angle between the line of sight and the axis of the accretion disk and
bolometric luminosity. Analysis of the obtained data shown that the spin value
decreases with cosmic time, which is in agreement with results of theoretical
calculations for low redshift AGNs of other authors. Also we found that the
spin value increases with the increasing mass of SMBH and bolometric
luminosity. This is the expected result that corresponds to theoretical
calculations. Analysis of the distribution of the spin values shown a
pronounced peak in the distribution in 0.75 < a < 1.0 range. ~ 40% of objects
have spin a > 0.75 and ~ 50% of objects have spin a > 0.5. This results are in
a good agreement with our previous results and with the results of other
authors.
- Termination of Superradiance from a Binary Companion
2205.10527 [abs] [pdf]
[abstract]
by Xi Tong, Yi Wang, and Hui-Yu Zhu.
We study the impact of a binary companion on black hole superradiance at
orbital frequencies away from the gravitational-collider-physics (GCP)
resonance bands. A superradiant state can couple to a strongly absorptive state
via the tidal perturbation of the companion, thereby acquiring a suppressed
superradiance rate. Below a critical binary separation, this superradiance rate
becomes negative, and the boson cloud gets absorbed by the black hole. This
critical binary separation leads to tight constraints on GCP. Especially, a
companion with mass ratio $q>10^{-3}$ invalidates all GCP fine structure
transitions, as well as almost all Bohr transitions except those from the
$|\psi_{211}\rangle$ state. Meanwhile, the backreaction on the companion
manifests itself as a torque acting on the binary, producing floating/sinking
orbits that can be verified via pulsar timing. In addition, the possible
termination of cloud growth may help to alleviate the current bounds on the
ultralight boson mass from various null detections.
- Parametric resonance in neutrino oscillations induced by ultra-light
dark matter and implications for KamLAND and JUNO
2205.09769 [abs] [pdf]
[abstract]
by Marta Losada, [and 4 more]Yosef Nir, Gilad Perez, Inbar Savoray, and Yogev Shpilman [hide authors].
If ultra-light dark matter (ULDM) exists and couples to neutrinos, the
neutrino oscillation probability might be significantly altered by a parametric
resonance. This resonance can occur if the typical frequency of neutrino
flavor-oscillations $\Delta m^2/(2E)$, where $\Delta m^2$ is the mass-squared
difference of the neutrinos and $E$ is the neutrino energy, matches the
oscillation frequency of the ULDM field, determined by its mass, $m_\phi$. The
resonance could lead to observable effects even if the ULDM coupling is very
small, and even if its typical oscillation period, given by
$\tau_\phi=2\pi/m_\phi$, is much shorter than the experimental temporal
resolution. Defining a small parameter $\epsilon_\phi$ to be the ratio between
the contribution of the ULDM field to the neutrino mass and the vacuum value of
the neutrino mass, the impact of the resonance is particularly significant if
$\epsilon_\phi m_\phi L\gtrsim 4$, where $L$ is the distance between the
neutrino source and the detector. Such parametric resonance can improve the fit
to the KamLAND experiment measurements by about $3.5\,\sigma$ compared to
standard oscillations. This scenario will be tested by the JUNO experiment.
- Detector Requirements for Model-Independent Measurements of Ultrahigh
Energy Neutrino Cross Sections
2205.09763 [abs] [pdf]
[abstract]
by Ivan Esteban, Steven Prohira, and John F. Beacom.
The ultrahigh energy range of neutrino physics (above $\sim 10^{7} \,
\mathrm{GeV}$), as yet devoid of detections, is an open landscape with
challenges to be met and discoveries to be made. Neutrino-nucleon cross
sections in that range - with center-of-momentum energies $\sqrt{s} \gtrsim 4
\, \mathrm{TeV}$ - are powerful probes of unexplored phenomena. We present a
simple and accurate model-independent framework to evaluate how well these
cross sections can be measured for an unknown flux and generic detectors. We
also demonstrate how to characterize and compare detector sensitivity. We show
that cross sections can be measured to $\simeq ^{+65}_{-30}$% precision over
$\sqrt{s} \simeq$ 4-140 TeV ($E_\nu = 10^7$-$10^{10}$ GeV) with modest energy
and angular resolution and $\simeq 10$ events per energy decade. Many allowed
novel-physics models (extra dimensions, leptoquarks, etc.) produce much larger
effects. In the distant future, with $\simeq 100$ events at the highest
energies, the precision would be $\simeq 15\%$, probing even QCD saturation
effects.
- Non-Universal Stellar Initial Mass Functions: Large Uncertainties in
Star Formation Rates at $z\approx 2-4$ and Other Astrophysical Probes
2205.07845 [abs] [pdf]
[abstract]
by Joshua J. Ziegler, [and 6 more]Thomas D. P. Edwards, Anna M. Suliga, Irene Tamborra, Shunsaku Horiuchi, Shin'ichiro Ando, and Katherine Freese [hide authors].
We explore the assumption, widely used in many astrophysical calculations,
that the stellar initial mass function (IMF) is universal across all galaxies.
By considering both a canonical Salpeter-like IMF and a non-universal IMF, we
are able to compare the effect of different IMFs on multiple observables and
derived quantities in astrophysics. Specifically, we consider a non-universal
IMF which varies as a function of the local star formation rate, and explore
the effects on the star formation rate density (SFRD), the extragalactic
background light, the supernova (both core-collapse and thermonuclear) rates,
and the diffuse supernova neutrino background. Our most interesting result is
that our adopted varying IMF leads to much greater uncertainty on the SFRD at
$z \approx 2-4$ than is usually assumed. Indeed, we find a SFRD (inferred using
observed galaxy luminosity distributions) that is a factor of $\gtrsim 3$ lower
than canonical results obtained using a universal Salpeter-like IMF. Secondly,
the non-universal IMF we explore implies a reduction in the supernova
core-collapse rate of a factor of $\sim2$, compared against a universal IMF.
The other potential tracers are only slightly affected by changes to the
properties of the IMF. We find that currently available data do not provide a
clear preference for universal or non-universal IMF. However, improvements to
measurements of the star formation rate and core-collapse supernova rate at
redshifts $z \gtrsim 2$ may offer the best prospects for discernment.
- Constraining super-light sterile neutrinos at Borexino and KamLAND
2205.07574 [abs] [pdf]
[abstract]
by Zikang Chen, [and 3 more]Jiajun Liao, Jiajie Ling, and Baobiao Yue [hide authors].
The presence of a super-light sterile neutrino can lead to a dip in the
survival probability of solar neutrinos, and explain the suppression of the
upturn in the low energy solar neutrino data. In this work, we systematically
study the survival probabilities in the 3+1 framework by taking into account of
the non-adiabatic transitions and the coherence effect. We obtain an analytic
equation that can predict the position of the dip. We also place constraints on
the parameter space of sterile neutrinos by using the latest Borexino and
KamLAND data. We find that the low and high energy neutrino data at Borexino
are sensitive to different regions in the sterile neutrino parameter space. In
the case with only $\theta_{01}$ being nonzero, the $\rm{{}^{8}B}$ data sets
the strongest bounds at $\Delta m_{01}^{2} \approx (1.1\sim2.2)\Delta
m_{21}^{2}$, while the low energy neutrino data is more sensitive to other
mass-squared regions. The lowest bounds on $\Delta m_{01}^{2}$ from the
$\rm{pp}$ data can reach $10^{-12} \ \rm{eV^{2}}$ because of the coherence
effect. Also, due to the presence of non-adiabatic transitions, the bounds in
the range of $10^{-9} \ \textrm{eV}^{2} \lesssim \Delta m_{01}^{2} \lesssim
10^{-5} \ \textrm{eV}^{2}$ become weaker as $\Delta m_{01}^{2}$ or
$\sin^{2}2\theta_{01}$ decreases. We also find that in the case with only
$\theta_{02}$ or $\theta_{03}$ being nonzero, the low energy solar neutrino
data set similar but weaker bounds as compared to the case with only
$\theta_{01}$ being nonzero. However, the bounds from the high energy solar
data and the KamLAND data are largely affected by the sterile mixing angles.
- Constraining Feeble Neutrino Interactions with Ultralight Dark Matter
2205.06821 [abs] [pdf]
[abstract]
by Abhish Dev, [and 3 more]Gordan Krnjaic, Pedro Machado, and Harikrishnan Ramani [hide authors].
If ultralight $(\ll$ eV), bosonic dark matter couples to right handed
neutrinos, active neutrino masses and mixing angles depend on the ambient dark
matter density. When the neutrino Majorana mass, induced by the dark matter
background, is small compared to the Dirac mass, neutrinos are "pseudo-Dirac"
fermions that undergo oscillations between nearly degenerate active and sterile
states.
We present a complete cosmological history for such a scenario and find
severe limits from a variety of terrestrial and cosmological observables. For
scalar masses in the "fuzzy" dark matter regime ($\sim 10^{-20}$ eV), these
limits exclude couplings of order $10^{-30}$, corresponding to Yukawa
interactions comparable to the gravitational force between neutrinos and
surpassing equivalent limits on time variation in scalar-induced electron and
proton couplings.
- Constraining Fundamental Constant Variations from Ultralight Dark Matter
with Pulsar Timing Arrays
2205.06817 [abs] [pdf]
[abstract]
by David E. Kaplan, Andrea Mitridate, and Tanner Trickle.
Pulsar Timing Arrays (PTAs) are exceptionally sensitive detectors in the
frequency band $\text{nHz} \lesssim f \lesssim \mu\text{Hz}$. Ultralight dark
matter (ULDM), with mass in the range $10^{-23}\,\text{eV} \lesssim m_\phi
\lesssim 10^{-20}\,\text{eV}$, is one class of DM models known to generate
signals in this frequency window. While purely gravitational signatures of ULDM
have been studied previously, in this work we consider two signals in PTAs
which arise in presence of direct couplings between ULDM and ordinary matter.
These couplings induce variations in fundamental constants, i.e., particle
masses and couplings. These variations can alter the moment of inertia of
pulsars, inducing pulsar spin fluctuations via conservation of angular
momentum, or induce apparent timing residuals due to reference clock shifts. By
using mock data mimicking current PTA datasets, we show that PTA experiments
outperform torsion balance and atomic clock constraints for ULDM coupled to
electrons, muons, or gluons. In the case of coupling to quarks or photons, we
find that PTAs and atomic clocks set similar constraints. Additionally, we
discuss how future PTAs can further improve these constraints, and detail the
unique properties of these signals relative to the previously studied effects
of ULDM on PTAs.
- Superradiant evolution of the shadow and photon ring of Sgr A$^\star$
2205.06238 [abs] [pdf]
[abstract]
by Yifan Chen, [and 3 more]Rittick Roy, Sunny Vagnozzi, and Luca Visinelli [hide authors].
Ultralight bosons can affect the dynamics of spinning black holes (BHs) via
superradiant instability, which can lead to a time evolution of the
supermassive BH shadow. We study prospects for witnessing the
superradiance-induced BH shadow evolution, considering ultralight vector and
tensor fields. We introduce two observables sensitive to the shadow
time-evolution: the shadow drift, and the variation in the azimuthal angle
lapse associated to the photon ring autocorrelation. The two observables are
shown to be highly complementary, depending on the observer's inclination
angle. Focusing on the supermassive object Sgr A$^\star$ we show that both
observables can vary appreciably over human timescales of a few years in the
presence of superradiant instability, leading to signatures which are well
within the reach of the Event Horizon Telescope for realistic observation times
(but benefiting significantly from extended observation periods), and paving
the way towards probing ultralight bosons in the $\sim 10^{-17}\,{\rm eV}$ mass
range.
- Discriminating between Lorentz violation and non-standard interactions
using core-passing atmospheric neutrinos at INO-ICAL
2205.05134 [abs] [pdf]
[abstract]
by Sadashiv Sahoo, [and 3 more]Anil Kumar, Sanjib Kumar Agarwalla, and Amol Dighe [hide authors].
Precision measurements of neutrino oscillation parameters have provided a
tremendous boost to the search for sub-leading effects due to several beyond
the Standard Model scenarios in neutrino oscillation experiments. Among these,
two of the well-studied scenarios are Lorentz violation (LV) and non-standard
interactions (NSI), both of which can affect neutrino oscillations
significantly. We point out that, at a long-baseline experiment where the
neutrino oscillation probabilities can be well-approximated by using the
line-averaged constant matter density, the effects of these two scenarios can
mimic each other. This would allow the limits obtained at such an experiment on
one of the above scenarios to be directly translated to the limits on the other
scenario. However, for the same reason, it would be difficult to distinguish
between LV and NSI at a long-baseline experiment. We show that the observations
of atmospheric neutrinos, which travel a wide range of baselines and may
encounter sharp density changes at the core-mantle boundary, can break this
degeneracy. We observe that identifying neutrinos and antineutrinos separately,
as can be done at INO-ICAL, can enhance the capability of atmospheric neutrino
experiments to discriminate between these two new-physics scenarios.
- First results of the nuGeN experiment on coherent elastic
neutrino-nucleus scattering
2205.04305 [abs] [pdf]
[abstract]
by I. Alekseev, [and 23 more]K. Balej, V. Belov, S. Evseev, D. Filosofov, M. Fomina, Z. Hons, D. Karaivanov, S. Kazartsev, J. Khushvaktov, A. Kuznetsov, A. Lubashevskiy, D. Medvedev, D. Ponomarev, A. Rakhimov, K. Shakhov, E. Shevchik, M. Shirchenko, K. Smolek, S. Rozov, I. Rozova, S. Vasilyev, E. Yakushev, and I. Zhitnikov [hide authors].
The nuGeN experiment is aimed to investigate neutrino properties using
antineutrinos from the reactor of the Kalinin Nuclear Power Plant. The
experimental setup is located at about 11 meters from the center of the 3.1
GWth reactor core. Scattering of the antineutrinos from the reactor is detected
with low energy threshold high purity germanium detector. Passive and active
shieldings are used to suppress all kinds of backgrounds coming from
surrounding materials and cosmic radiation. The description of the experimental
setup together with the first results is presented. The data taken in regimes
with reactor ON (94.50 days) and reactor OFF (47.09 days) have been compared.
No significant difference between spectra of two data sets is observed, i.e. no
positive signals for coherent elastic neutrino-nucleus scattering are detected.
Under Standard Model assumptions about coherent neutrino scattering an upper
limit on a quenching parameter k < 0.26 (90 \% C.L.) in germanium has been set.
- Vector leptoquark $U_3$ and CP violation at T2K, NOvA experiments
2205.04269 [abs] [pdf]
[abstract]
by Rudra Majhi, [and 3 more]Dinesh Kumar Singha, K. N. Deepthi, and Rukmani Mohanta [hide authors].
In the current epoch of neutrino physics, many experiments are aiming for
precision measurements of oscillation parameters. Thus, various new physics
scenarios which alter the neutrino oscillation probabilities in matter deserve
careful investigation. In this context, we study the effect of a vector
leptoquark which induces non-standard neutrino interactions (NSI) that modify
the oscillation probabilities of neutrinos in matter. We show that such
interactions provide a relatively large value of NSI parameter $\varepsilon_{e
\mu}$. Considering this NSI parameter, we successfully explain the recent
discrepancy between the observed $\delta_{CP}$ results of T2K and NOvA.
- Multi-messenger High-Energy Signatures of Decaying Dark Matter and the
Effect of Background Light
2205.03416 [abs] [pdf]
[abstract]
by Barbara Skrzypek, Marco Chianese, and Carlos Argüelles Delgado.
The IceCube Neutrino Observatory at the South Pole has measured astrophysical
neutrinos using through-going and starting events in the TeV to PeV energy
range. The origin of these astrophysical neutrinos is still largely unresolved,
and among their potential sources could be dark matter decay. Measurements of
the astrophysical flux using muon neutrinos are in slight tension with starting
event measurements. This tension is driven by an excess observed in the energy
range of 40-200 TeV with respect to the through-going expectation. Previous
works have considered the possibility that this excess may be due to heavy dark
matter decay and have placed constraints using gamma-ray and neutrino data.
However, these constraints are not without caveats since they rely on the
modeling of the astrophysical neutrino flux and the sources of gamma-ray
emission. In this work, we derive background-agnostic galactic and
extragalactic constraints on decaying dark matter by considering Tibet
AS$_\gamma$ data, Fermi-LAT diffuse data, and the IceCube high-energy starting
event sample. For the gamma-ray limits, we investigate the uncertainties on
secondary emission from electromagnetic cascades during propagation arising
from the unknown intensity of the extragalactic background light. We find that
such uncertainties amount to a variation of up to $\sim 55\%$ in the gamma-ray
limits derived with extragalactic data. Our results imply that a significant
fraction of the astrophysical neutrino flux could be due to dark matter and
that ruling it out depends on the assumptions on the gamma-ray and neutrino
background. The latter depends on the yet unidentified sources.
- Matter effects on flavor transitions of high-energy astrophysical
neutrinos based on different decoherence schemes
2205.03164 [abs] [pdf]
[abstract]
by Ding-Hui Xu and Shu-Jun Rong.
The progress of neutrino astronomy makes the precise measurement of the
flavor ratio of high energy astronomical neutrinos (HANs) possible in the near
future. Then matter effects and new physics effects on the flavor transition of
HANs could be tested by the next-generation neutrino telescopes. In this paper
we study matter effects in gas around the sources of HANs. The matter effects
are dependent on both the decoherence schemes and the sources of neutrinos. We
examine the predictions on the flavor ratio at Earth for typical sources with
five decoherence schemes. For the adiabatic schemes, the matter effect is
notable and may be identified in the special range of the electron density,
irrespective of the production sources of HANs. Hence, the precise measurement
of the flavor ratio would provide constrains on the propagation schemes and the
matter parameter.
- Confronting the prediction of leptonic Dirac CP-violating phase with
experiments
2205.02796 [abs] [pdf]
[abstract]
by Yang Hwan Ahn, [and 3 more]Sin Kyu Kang, Raymundo Ramos, and Morimitsu Tanimoto [hide authors].
We update and improve past efforts to predict the leptonic Dirac CP-violating
phase with models that predict perturbatively modified tribimaximal or
bimaximal mixing. Simple perturbations are applied to both mixing patterns in
the form of rotations between two sectors. By translating these perturbed
mixing matrices to the standard parameterization for the neutrino mixing matrix
we derive relations between the Dirac CP-phase and the oscillation angles. We
use these relations together with current experimental results to constrain the
allowed range for the CP-phase and determine its probability density.
Furthermore, we elaborate on the prospects for future experiments probing on
the perturbations considered in this work. We present a model with $A_4$
modular symmetry that is consistent with one of the described perturbed
scenarios and successfully predicts current oscillation parameter data.
- Neutrino mass and mass ordering: No conclusive evidence for normal
ordering
2205.02195 [abs] [pdf]
[abstract]
by Stefano Gariazzo, [and 10 more]Martina Gerbino, Thejs Brinckmann, Massimiliano Lattanzi, Olga Mena, Thomas Schwetz, Shouvik Roy Choudhury, Katherine Freese, Steen Hannestad, Christoph A. Ternes, and Mariam Tórtola [hide authors].
The extraction of the neutrino mass ordering is one of the major challenges
in particle physics and cosmology, not only for its implications for a
fundamental theory of mass generation in nature, but also for its decisive role
in the scale of future neutrinoless double beta decay experimental searches. It
has been recently claimed that current oscillation, beta decay and cosmological
limits on the different observables describing the neutrino mass parameter
space provide robust decisive Bayesian evidence in favor of the normal ordering
of the neutrino mass spectrum [arXiv:2203.14247]. We further investigate these
strong claims using a rich and wide phenomenology, with different sampling
techniques of the neutrino parameter space. Contrary to the findings of Jimenez
et al [arXiv:2203.14247], no decisive evidence for the normal mass ordering is
found. Neutrino mass ordering analyses must rely on priors and
parameterizations that are ordering-agnostic: robust results should be regarded
as those in which the preference for the normal neutrino mass ordering is
driven exclusively by the data, while we find a difference of up to a factor of
33 in the Bayes factors among the different priors and parameterizations
exploited here. An ordering-agnostic prior would be represented by the case of
parameterizations sampling over the two mass splittings and a mass scale, or
those sampling over the individual neutrino masses via normal prior
distributions only. In this regard, we show that the current significance in
favor of the normal mass ordering should be taken as $2.7\sigma$ (i.e. moderate
evidence), mostly driven by neutrino oscillation data.
- The diffuse supernova neutrino background as a probe of late-time
neutrino mass generation
2205.01102 [abs] [pdf]
[abstract]
by André de Gouvêa, [and 3 more]Ivan Martinez-Soler, Yuber F. Perez-Gonzalez, and Manibrata Sen [hide authors].
The relic neutrinos from old supernova explosions are among the most ancient
neutrino fluxes within experimental reach. Thus, the diffuse supernova neutrino
background (DSNB) could teach us if neutrino masses were different in the past
(redshifts $z\lesssim 5$). Oscillations inside the supernova depend strongly on
the neutrino mass-squared differences and the values of the mixing angles,
rendering the DSNB energy spectrum sensitive to variations of these parameters.
Considering a purely phenomenological parameterization of the neutrino masses
as a function of redshift, we compute the expected local DSNB spectrum here on
Earth. Given the current knowledge of neutrino oscillation parameters,
specially the fact that $|U_{e3}|^2$ is small, we find that the $\nu_e$
spectrum could be significantly different from standard expectations if
neutrinos were effectively massless at $z\gtrsim1$ as long as the neutrino mass
ordering is normal. On the other hand, the $\overline{\nu}_e$ flux is not
expected to be significantly impacted. Hence, a measurement of both the
neutrino and antineutrino components of the DSNB should allow one to test the
possibility of recent neutrino mass generation.
April 2022
- Compatibility of Neutrino DIS Data and Its Impact on Nuclear Parton
Distribution Functions
2204.13157 [abs] [pdf]
[abstract]
by K. F. Muzakka, [and 11 more]P. Duwentäster, T. J. Hobbs, T. Ježo, M. Klasen, K. Kovařík, A. Kusina, J. G. Morfín, F. I. Olness, R. Ruiz, I. Schienbein, and J. Y. Yu [hide authors].
In global analyses of nuclear parton distribution functions (nPDFs), neutrino
deep-inelastic scattering (DIS) data have been argued to exhibit tensions with
the data from charged-lepton DIS. Using the nCTEQ framework, we investigate
these possible tensions both internally and with the data sets used in our
recent nPDF analysis nCTEQ15WZSIH. We take into account nuclear effects in the
calculation of the deuteron structure function $F_2^D$ using the CJ15 analysis.
The resulting nPDF fit, nCTEQ15WZSIHdeut, serves as the basis for our
comparison with inclusive neutrino DIS and charm dimuon production data. Using
$\chi^2$ hypothesis testing, we confirm evidence of tensions with these data
and study the impact of the proton PDF baseline as well as the treatment of
data correlation and normalization uncertainties. We identify the experimental
data and kinematic regions that generate the tensions and present several
possible approaches how a consistent global analysis with neutrino data can be
performed. We show that the tension can be relieved using a kinematic cut at
low $x$ ($x>0.1$) and also investigate a possibility of managing the tensions
by using uncorrelated systematic errors. Finally, we present a different
approach identifying a subset of neutrino data which leads to a consistent
global analysis without any additional cuts. Understanding these tensions
between the neutrino and charged-lepton DIS data is important not only for a
better flavor separation in global analyses of nuclear and proton PDFs, but
also for neutrino physics and for searches for physics beyond the Standard
Model.
- Timing and Multi-Channel: Novel Method for Determining the Neutrino Mass
Ordering from Supernovae
2204.13135 [abs] [pdf]
[abstract]
by Vedran Brdar and Xun-Jie Xu.
One of the few remaining unknowns in the standard three-flavor neutrino
oscillation paradigm is the ordering of neutrino masses. In this work we
propose a novel method for determining neutrino mass ordering using the time
information on early supernova neutrino events. In a core-collapse supernova,
neutrinos are produced earlier than antineutrinos and, depending on the mass
ordering which affects the adiabatic flavor evolution, may cause earlier
observable signals in $\nu_e$ detection channels than in others. Hence, the
time differences are sensitive to the mass ordering. We find that using the
time information on the detection of the first galactic supernova events at
future detectors like DUNE, JUNO and Hyper-Kamiokande, the mass ordering can
already be determined at $\sim 2 \sigma$ CL, while $\mathcal{O}(10)$ events
suffice for the discovery. Our method does not require high statistics and
could be used within the supernova early warning system (SNEWS) which will have
access to the time information on early supernova neutrino events recorded in a
number of detectors. The method proposed in this paper also implies a crucial
interplay between the mass ordering and the triangulation method for locating
supernovae.
- Antineutrino sensitivity at THEIA
2204.12278 [abs] [pdf]
[abstract]
by Stephane Zsoldos, [and 4 more]Zara Bagdasarian, Gabriel D. Orebi Gann, Andrew Barna, and Stephen Dye [hide authors].
We present the sensitivity of the Theia experiment to low-energy geo- and
reactor antineutrinos. For this study, we consider one of the possible proposed
designs, a 17.8-ktonne fiducial volume Theia-25 detector filled with
water-based liquid scintillator placed at Sanford Underground Research Facility
(SURF). We demonstrate Theia's sensitivity to measure the geo- and reactor
antineutrinos via Inverse-Beta Decay interactions after one year of data taking
with $11.9\times10^{32}$ free target protons. The expected number of detected
geo- and reactor antineutrinos is $218\,^{+28}_{-20}$ and $170\,^{+24}_{-20}$,
respectively. The precision of the fitting procedure has been evaluated to be
6.72% and 8.55% for geo- and reactor antineutrinos, respectively. We also
demonstrate the sensitivity towards fitting individual Th and U contributions,
with best fit values of $N_\text{Th}=39\,^{+18}_{-15}$ and
$N_\text{U}=180\,^{+26}_{-22}$. We obtain $(\text{Th}/\text{U})=4.3\pm2.6$
after one year of data taking, and within ten years, the relative precision of
the (Th/U) mass ratio will be reduced to 15%. Finally, from the fit results of
individual Th and U contributions, we evaluate the mantle signal to be
$S_\text{mantle} = 9.0\,\pm [4.2,4.5]$NIU. This was obtained assuming a
full-range positive correlation ($\rho_c\in[0, 1]$) between Th and U, and the
projected uncertainties on the crust contributions of 8.3% (Th) and 7.0% (U).
When considering systematic uncertainties on the signal and background shape
and fluxes, the mantle signal becomes $S_\text{mantle} = 9.3\,\pm
[5.2,5.4]$NIU.
- Microscopic and Macroscopic Effects in the Decoherence of Neutrino
Oscillations
2204.10696 [abs] [pdf]
[abstract]
by Ting Cheng, Manfred Lindner, and Werner Rodejohann.
We present a generic structure (the layer structure) for decoherence effects
in neutrino oscillations, which includes decoherence from quantum mechanical
and classical uncertainties. The calculation is done by combining the concept
of open quantum system and quantum field theory, forming a structure composed
of phase spaces from microscopic to macroscopic level. Having information loss
at different levels, quantum mechanical uncertainties parameterize decoherence
by an intrinsic mass eigenstate separation effect, while decoherence for
classical uncertainties is typically dominated by a statistical averaging
effect. With the help of the layer structure, we classify the former as state
decoherence (SD) and the latter as phase decoherence (PD), then further
conclude that both SD and PD result from phase wash-out effects of different
phase structures on different layers. Such effects admit for simple numerical
calculations of decoherence for a given width and shape of uncertainties. While
our structure is generic, so are the uncertainties, nonetheless, a few notable
ones are: the wavepacket size of the external particles, the effective
interaction volume at production and detection, the energy reconstruction model
and the neutrino production profile. Furthermore, we estimate the experimental
sensitivities for SD and PD parameterized by the uncertainty parameters, for
reactor neutrinos and decay-at-rest neutrinos, using a traditional rate
measuring method and a novel phase measuring method.
- Very Light Sterile Neutrinos at NOvA and T2K
2204.09130 [abs] [pdf]
[abstract]
by André de Gouvêa, Giancarlo Jusino Sánchez, and Kevin J. Kelly.
Over the last several years, our understanding of neutrino oscillations has
developed significantly due to the long-baseline measurements of muon-neutrino
disappearance and muon-to-electron-neutrino appearance at the T2K and NOvA
experiments. However, when interpreted under the
standard-three-massive-neutrinos paradigm, a tension has emerged between the
two experiments' data. Here, we examine whether this tension can be alleviated
when a fourth, very light neutrino is added to the picture. Specifically, we
focus on the scenario in which this new neutrino has a mass similar to, or even
lighter than, the three mostly-active neutrinos that have been identified to
date. We find that, for some regions of parameter space, the four-neutrino
framework is favored over the three-neutrino one with moderate (a little under
two sigma) significance. Interpreting these results, we provide future outlook
for near-term and long-term experiments if this four-neutrino framework is
indeed true.
- New reactor data improves robustness of neutrino mass ordering
determination
2204.09060 [abs] [pdf]
[abstract]
by Peter B. Denton and Julia Gehrlein.
In neutrino oscillation physics numerous exact degeneracies exist under the
name LMA-Dark. These degeneracies make it impossible to determine the sign of
$\Delta m^2_{31}$ known as the atmospheric mass ordering with oscillation
experiments alone in the presence of new neutrino interactions. The combination
of different measurements including multiple oscillation channels and neutrino
scattering experiments lifts some aspects of these degeneracies. In fact,
previous measurements of coherent elastic neutrino nucleus scattering (CEvNS)
by COHERENT already ruled out the LMA-Dark solution for new physics with
mediators heavier than $M_{Z'}\sim50$ MeV while cosmological considerations
disfavor these scenarios for mediators lighter than $M_{Z'}\sim3$ MeV. Here we
leverage new data from the Dresden-II experiment which provides the strongest
bounds on CEvNS with reactor neutrinos to date. We show that this data
completely removes the degeneracies in the $\nu_e$ sector for mediators down to
the MeV scale at which point constraints from the early universe take over.
While the LMA-Dark degeneracy is lifted in the $\nu_e$ sector, it can still be
restored in the $\nu_\mu$ and $\nu_\tau$ sector or with very specific couplings
to up and down quarks, and we speculate on a path forward.
- Independent determination of the Earth's orbital parameters with solar
neutrinos in Borexino
2204.07029 [abs] [pdf]
[abstract]
by S. Appel, [and 78 more]Z. Bagdasarian, D. Basilico, G. Bellini, J. Benziger, R. Biondi, B. Caccianiga, F. Calaprice, A. Caminata, A. Chepurnov, D. D'Angelo, A. Derbin, A. Di Giacinto, V. Di Marcello, X. F. Ding, A. Di Ludovico, L. Di Noto, I. Drachnev, D. Franco, C. Galbiati, C. Ghiano, M. Giammarchi, A. Goretti, A. S. Goettel, M. Gromov, D. Guffanti, Aldo Ianni, Andrea Ianni, A. Jany, V. Kobychev, G. Korga, S. Kumaran, M. Laubenstein, E. Litvinovich, P. Lombardi, I. Lomskaya, L. Ludhova, G. Lukyanchenko, I. Machulin, J. Martyn, E. Meroni, L. Miramonti, M. Misiaszek, V. Muratova, R. Nugmanov, L. Oberauer, V. Orekhov, F. Ortica, M. Pallavicini, L. Pelicci, O. Penek, L. Pietrofaccia, N. Pilipenko, A. Pocar, G. Raikov, M. T. Ranalli, G. Ranucci, A. Razeto, A. Re, M. Redchuk, N. Rossi, S. Schoenert, D. Semenov, G. Settanta, M. Skorokhvatov, A. Singhal, O. Smirnov, A. Sotnikov, R. Tartaglia, G. Testera, E. Unzhakov, A. Vishneva, R. B. Vogelaar, F. von Feilitzsch, M. Wojcik, M. Wurm, S. Zavatarelli, K. Zuber, and G. Zuzel [hide authors].
Since the beginning of 2012, the Borexino collaboration has been reporting
precision measurements of the solar neutrino fluxes, emitted in the
proton-proton chain and in the Carbon-Nitrogen-Oxygen cycle. The experimental
sensitivity achieved in Phase-II and Phase-III of the Borexino data taking made
it possible to detect the annual modulation of the solar neutrino interaction
rate due to the eccentricity of Earth's orbit, with a statistical significance
greater than 5$\sigma$. This is the first precise measurement of the Earth's
orbital parameters based solely on solar neutrinos and an additional signature
of the solar origin of the Borexino signal. The complete periodogram of the
time series of the Borexino solar neutrino detection rate is also reported,
exploring frequencies between one cycle/year and one cycle/day. No other
significant modulation frequencies are found. The present results were uniquely
made possible by Borexino's decade-long high-precision solar neutrino
detection.
- Analytic treatment of 3-flavor neutrino oscillation and decay in matter
2204.05803 [abs] [pdf]
[abstract]
by Dibya S. Chattopadhyay, [and 3 more]Kaustav Chakraborty, Amol Dighe, and Srubabati Goswami [hide authors].
We present compact analytic expressions for 3-flavor neutrino oscillation
probabilities with invisible neutrino decay, where matter effects have been
explicitly included. We take into account the possibility that the oscillation
and decay components of the effective Hamiltonian do not commute. This is
achieved by employing the techniques of inverse Baker-Campbell-Hausdorff (BCH)
expansion and the Cayley-Hamilton theorem applied in the 3-flavor framework. If
only the vacuum mass eigenstate $\nu_3$ decays, we show that the treatment of
neutrino propagation may be reduced to an effective 2-flavor analysis in the
One Mass Scale Dominance (OMSD) approximation. The oscillation probabilities
for $P_{\mu\mu}$, $P_{ee}$, $P_{e\mu}$ and $P_{\mu e}$ -- relevant for reactor,
long baseline and atmospheric neutrino experiments -- are obtained as
perturbative expansions for the case of only $\nu_3$ decay, as well as for the
more general scenario where all components of the decay matrix are non-zero.
The analytic results thus obtained match the exact numerical results for
constant density matter to a high precision and provide physical insights into
possible effects of the decay of neutrinos as they propagate through Earth
matter. We find that the effects of neutrino decay are most likely to be
observable in $P_{\mu\mu}$. We also point out that at any long baseline, the
oscillation dips in $P_{\mu\mu}$ can show higher survival probabilities in the
case with decay than without decay, and explain this feature using our analytic
approximations.
- Exploring the Fate of Stellar Core Collapse with Supernova Relic
Neutrinos
2204.04880 [abs] [pdf]
[abstract]
by Yosuke Ashida and Ken'ichiro Nakazato.
Core collapse of massive stars leads to different fates for various physical
factors, which gives different spectra of the emitted neutrinos. We focus on
the supernova relic neutrinos (SRNs) as a probe to investigate the stellar
collapse fate. We present the SRN fluxes and event rate spectra at a detector
for three resultant states after stellar core collapse, the typical mass
neutron star, the higher mass neutron star, or the failed supernova forming a
black hole, based on different nuclear equations of state. Then possible SRN
fluxes are formed as mixtures of the three components. We also show the
expected sensitivities at the next-generation water-based Cherenkov detectors,
SK-Gd and Hyper-Kamiokande, as constraining the mixture fractions. This study
provides a practical example of extracting astrophysical constraints through
SRN measurement.
- Sterile neutrino production at small mixing in the early universe
2204.04224 [abs] [pdf]
[abstract]
by Gonzalo Alonso-Álvarez and James M. Cline.
Sterile neutrinos can be produced in the early universe via interactions with
their active counterparts. For small active-sterile mixing angles, thermal
equilibrium with the standard model plasma is not reached and sterile neutrinos
are only produced via flavor oscillations. We study in detail this regime,
taking into account matter potentials and decoherence effects caused by elastic
scatterings with the plasma. We find that resonant oscillations occurring at
temperatures $T\lesssim 10\,\mathrm{GeV}$ lead to a significant enhancement of
the sterile neutrino production rate. Taking this into account, we improve
constraints on the active-sterile mixing from Big Bang nucleosynthesis and the
cosmic microwave background, excluding mixing angles down to $\theta_s\sim
10^{-10}-10^{-16}$ for sterile neutrino masses in the $10\,\mathrm{MeV}$ to
$10\,\mathrm{GeV}$ range. We observe that if sterile neutrinos predominantly
decay into metastable hidden sector particles, this process provides a novel
dark matter production mechanism, consistent with the sterile neutrino origin
of light neutrino masses via the seesaw mechanism.
- Constraining New Physics with Borexino Phase-II spectral data
2204.03011 [abs] [pdf]
[abstract]
by Pilar Coloma, [and 4 more]M. C. Gonzalez-Garcia, Michele Maltoni, João Paulo Pinheiro, and Salvador Urrea [hide authors].
We present a detailed analysis of the spectral data of Borexino Phase II,
with the aim of exploiting its full potential to constrain scenarios beyond the
Standard Model. In particular, we quantify the constraints imposed on neutrino
magnetic moments, neutrino non-standard interactions, and several simplified
models with light scalar, pseudoscalar or vector mediators. Our analysis shows
perfect agreement with those performed by the collaboration on neutrino
magnetic moments and neutrino non-standard interactions in the same restricted
cases and expands beyond those, stressing the interplay between flavour
oscillations and flavour non-diagonal interaction effects for the correct
evaluation of the event rates. For simplified models with light mediators we
show the power of the spectral data to obtain robust limits beyond those
previously estimated in the literature.
- Cored Dark Matter halos in the Cosmic Neutrino Background
2204.01431 [abs] [pdf]
[abstract]
by Wonsub Cho, Ki-Young Choi, and Hee Jung Kim.
We study the impact of the interaction between DM and the cosmic neutrino
background on the evolution of galactic dark matter halos. The energy transfer
from the neutrinos to the dark matter can heat the center of the galaxy and
make it cored. This effect is efficient for the small galaxies such as the
satellite galaxies of the Milky Way and we can put conservative constraint on
the non-relativistic elastic scattering cross section as
$\sigma_{\chi\nu}\lesssim 10^{-31} {\rm cm}^2$ for 0.1 keV dark matter and 0.1
eV neutrino.
March 2022
- Visible Neutrino Decays and the Impact of the Daughter-Neutrino Mass
2203.14976 [abs] [pdf]
[abstract]
by André de Gouvêa, Manibrata Sen, and Jean Weill.
We compute the differential decay width of two- and three-body neutrino
decays, assuming neutrinos are Dirac fermions and allowing for the possibility
that the decay-daughters have nonzero masses. We examine different hypotheses
for the interaction that mediates neutrino decay and concentrate on identifying
circumstances where the decay-daughters can significantly impact the
neutrino-decay signature at different experiments. We are especially interested
in decay daughters produced by right-chiral neutrino fields, when the mass of
the daughter plays a decisive role. As a concrete example, we compare the
effects of visible and invisible antineutrino decays at the JUNO experimental
setup.
- Neutrino Masses and Mass Hierarchy: Evidence for the Normal Hierarchy
2203.14247 [abs] [pdf]
[abstract]
by Raul Jimenez, [and 4 more]Carlos Pena-Garay, Kathleen Short, Fergus Simpson, and Licia Verde [hide authors].
The latest cosmological constraints on the sum of neutrino masses, in
combination with the latest laboratory measurements on oscillations, provide
``decisive" Bayesian evidence for the normal neutrino mass hierarchy. We show
that this result holds across very different prior alternatives by exploring
two extremes on the range of prior choices. In fact, while the specific
numerical value for the Evidence depends on the choice of prior, the Bayesian
odds remain greater than 140:1 across very different prior choices. For
Majorana neutrinos this has important implications for the upper limit of the
neutrino-less double beta decay half life and thus for the technology and
resources needed for future double beta decay experiments.
- PeV Tau Neutrinos to Unveil Ultra-High-Energy Sources
2203.13827 [abs] [pdf]
[abstract]
by Carlos A. Argüelles, [and 3 more]Francis Halzen, Ali Kheirandish, and Ibrahim Safa [hide authors].
The observation of ultra-high-energy EeV-energy cosmogenic neutrinos provides
a direct path to identifying the sources of the highest energy cosmic rays;
searches have so far resulted in only upper limits on their flux. However, with
the realization of cubic-kilometer detectors such as IceCube and, in the near
future, KM3NeT, GVD-Baikal, and similar instruments, we anticipate the
observation of PeV-energy cosmic neutrinos with high statistics. In this
context, we draw attention to the opportunity to identify EeV tau neutrinos at
PeV energy using Earth-traversing tau neutrinos. We show that Cherenkov
detectors can improve their sensitivity to transient point sources by more than
an order of magnitude by indirectly observing EeV tau neutrinos with initial
energies that are nominally beyond their reach. This new technique also
improves their sensitivity to the ultra-high-energy diffuse neutrino flux by up
to a factor of two. Our work exemplifies how observing tau neutrinos at PeV
energies provides an unprecedented reach to EeV fluxes.
- No CC-NSI explanation of the Gallium anomaly
2203.13659 [abs] [pdf]
[abstract]
by Carlo Giunti and Christoph Andreas Ternes.
We show that the Gallium anomaly can not be explained by CC-NSI.
- Rocks, Water and Noble Liquids: Unfolding the Flavor Contents of
Supernova Neutrinos
2203.12696 [abs] [pdf]
[abstract]
by Sebastian Baum, Francesco Capozzi, and Shunsaku Horiuchi.
Measuring core-collapse supernova neutrinos, both from individual supernovae
within the Milky Way and from past core collapses throughout the Universe (the
diffuse supernova neutrino background, or DSNB), is one of the main goals of
current and next generation neutrino experiments. Detecting the heavy-lepton
flavor (muon and tau types, collectively $\nu_x$) component of the flux is
particularly challenging due to small statistics and large backgrounds. While
the next galactic neutrino burst will be observed in a plethora of neutrino
channels, allowing to measure a small number of $\nu_x$ events, only upper
limits are anticipated for the diffuse $\nu_x$ flux even after decades of data
taking with conventional detectors. However, paleo-detectors could measure the
time-integrated flux of neutrinos from galactic core-collapse supernovae via
flavor-blind neutral current interactions. In this work, we show how combining
a measurement of the average galactic core-collapse supernova flux with paleo
detectors and measurements of the DSNB electron-type neutrino fluxes with the
next-generation water Cherenkov detector Hyper-Kamiokande and the liquid noble
gas detector DUNE will allow to determine the mean supernova $\nu_x$ flux
parameters with precision of order ten percent.
- Testing Non-Standard Interactions Between Solar Neutrinos and Quarks
with Super-Kamiokande
2203.11772 [abs] [pdf]
[abstract]
by Super-Kamiokande Collaboration, [and 272 more]:, P. Weatherly, K. Abe, C. Bronner, Y. Hayato, K. Hiraide, M. Ikeda, K. Iyogi, J. Kameda, Y. Kanemura, Y. Kataoka, Y. Kato, Y. Kishimoto, S. Miki, M. Miura, S. Moriyama, T. Mochizuki, M. Nakahata, Y. Nakano, S. Nakayama, T. Okada, K. Okamoto, A. Orii, G. Pronost, K. Sato, H. Sekiya, M. Shiozawa, Y. Sonoda, Y. Suzuki, A. Takeda, Y. Takemoto, A. Takenaka, H. Tanaka, S. Tasaka, X. Wang, S. Watanabe, T. Yano, S. Han, T. Kajita, K. Kaneyuki, K. Okumura, T. Tashiro, R. Wang, J. Xia, G. D. Megias, L. Labarga, B. Zaldivar, B. W. Pointon, F. d. M. Blaszczyk, C. Kachulis, E. Kearns, J. L. Raaf, J. L. Stone, L. R. Sulak, S. Sussman, L. Wan, T. Wester, S. Berkman, S. Tobayama, J. Bian, M. Elnimr, N. J. Griskevich, W. R. Kropp, S. Locke, S. Mine, M. B. Smy, H. W. Sobel, V. Takhistov, A. Yankelevich, K. S. Ganezer, J. Hill, J. Y. Kim, I. T. Lim, R. G. Park, B. Bodur, Z. Li, K. Scholberg, C. W. Walter, L. Bernard, A. Coffani, O. Drapier, A. Giampaolo, S. El Hedri, J. Imber, Th. A. Mueller, P. Paganini, B. Quilain, A. D. Santos, T. Ishizuka, T. Nakamura, J. S. Jang, J. G. Learned, S. Matsuno, S. Cao, J. Amey, L. H. V. Anthony, R. P. Litchfield, W. Y. Ma, D. Martin, M. Scott, A. A. Sztuc, Y. Uchida, M. O. Wascko, V. Berardi, M. G. Catanesi, R. A. Intonti, E. Radicioni, N. F. Calabria, L. N. Machado, G. De Rosa, G. Collazuol, F. Iacob, M. Lamoureux, M. Mattiazzi, N. Ospina, L. Ludovici, M. Gonin, Y. Maekawa, Y. Nishimura, M. Friend, T. Hasegawa, T. Ishida, M. Jakkapu, T. Kobayashi, T. Matsubara, T. Nakadaira, K. Nakamura, Y. Oyama, K. Sakashita, T. Sekiguchi, T. Tsukamoto, T. Boschi, F. Di Lodovico, J. Gao, T. Katori, J. Migenda, M. Taani, S. Zsoldos, KE. Abe, M. Hasegawa, Y. Isobe, Y. Kotsar, H. Miyabe, H. Ozaki, T. Sugimoto, A. T. Suzuki, Y. Takeuchi, S. Yamamoto, Y. Ashida, J. Feng, T. Hayashino, S. Hirota, M. Jiang, T. Kikawa, M. Mori, T. Nakaya, R. A. Wendell, K. Yasutome, P. Fernandez, N. McCauley, P. Mehta, A. Pritchard, K. M. Tsui, Y. Fukuda, Y. Itow, H. Menjo, M. Murase, K. Frankiewicz, J. Lagoda, S. M. Lakshmi, M. Mandal, P. Mijakowski, Y. S. Prabhu, J. Zalipska, M. Jia, J. Jiang, C. K. Jung, X. Li, J. L. Palomino, G. Santucci, C. Vilela, M. J. Wilking, C. Yanagisawa, D. Fukuda, K. Hagiwara, M. Harada, H. Ishino, S. Ito, H. Kitagawa, Y. Koshio, W. Ma, S. Sakai, M. Sakuda, Y. Takahira, C. Xu, Y. Kuno, G. Barr, D. Barrow, L. Cook, A. Goldsack, S. Samani, C. Simpson, D. Wark, S. Molina Sedgwick, R. Tacik, F. Nova, J. Y. Yang, S. J. Jenkins, M. Malek, J. M. McElwee, O. Stone, M. D. Thiesse, L. F. Thompson, H. Okazawa, Y. Choi, S. B. Kim, J. W. Seo, I. Yu, A. Ichikawa, K. D. Nakamura, K. Nishijima, M. Koshiba, K. Iwamoto, K. Nakagiri, Y. Nakajima, Y. Suda, N. Taniuchi, M. Yokoyama, K. Martens, M. Murdoch, M. R. Vagins, D. Hamabe, S. Izumiyama, M. Kuze, Y. Okajima, T. Yoshida, M. Inomoto, M. Ishitsuka, H. Ito, T. Kinoshita, R. Matsumoto, M. Shinoki, T. Suganuma, M. Yonenaga, J. F. Martin, C. M. Nantais, H. A. Tanaka, T. Towstego, R. Akutsu, P. de Perio, V. Gousy-Leblanc, M. Hartz, A. Konaka, P. de Perio, N. W. Prouse, S. Chen, B. D. Xu, B. Zhang, M. Posiadala-Zezula, D. Hadley, M. Nicholson, M. O'Flaherty, B. Richards, A. Ali, B. Jamieson, P. Giorgio, Ll. Marti, A. Minamino, G. Pintaudi, S. Sano, R. Sasaki, and K. Wada [hide authors].
Non-Standard Interactions (NSI) between neutrinos and matter affect the
neutrino flavor oscillations. Due to the high matter density in the core of the
Sun, solar neutrinos are suited to probe these interactions. Using the $277$
kton-yr exposure of Super-Kamiokande to $^{8}$B solar neutrinos, we search for
the presence of NSI. Our data favors the presence of NSI with down quarks at
1.8$\sigma$, and with up quarks at 1.6$\sigma$, with the best fit NSI
parameters being ($\epsilon_{11}^{d},\epsilon_{12}^{d}$) = (-3.3, -3.1) for
$d$-quarks and ($\epsilon_{11}^{u},\epsilon_{12}^{u}$) = (-2.5, -3.1) for
$u$-quarks. After combining with data from the Sudbury Neutrino Observatory and
Borexino, the significance increases by 0.1$\sigma$.
- Snowmass White Paper: Beyond the Standard Model effects on Neutrino
Flavor
2203.10811 [abs] [pdf]
[abstract]
by C. A. Argüelles, [and 25 more]G. Barenboim, M. Bustamante, P. Coloma, P. B. Denton, I. Esteban, Y. Farzan, E. Fernández Martínez, D. V. Forero, A. M. Gago, T. Katori, R. Lehnert, M. Ross-Lonergan, A. M. Suliga, Z. Tabrizi, L. Anchordoqui, K. Chakraborty, J. Conrad, A. Das, C. S. Fong, B. R. Littlejohn, M. Maltoni, D. Parno, J. Spitz, J. Tang, and S. Wissel [hide authors].
Neutrinos are one of the most promising messengers for signals of new physics
Beyond the Standard Model (BSM). On the theoretical side, their elusive nature,
combined with their unknown mass mechanism, seems to indicate that the neutrino
sector is indeed opening a window to new physics. On the experimental side,
several long-standing anomalies have been reported in the past decades,
providing a strong motivation to thoroughly test the standard three-neutrino
oscillation paradigm. In this Snowmass21 white paper, we explore the potential
of current and future neutrino experiments to explore BSM effects on neutrino
flavor during the next decade.
- Constraining ultra-high-energy cosmic ray composition through
cross-correlations
2203.09538 [abs] [pdf]
[abstract]
by Konstantinos Tanidis, Federico R. Urban, and Stefano Camera.
The chemical composition of the highest end of the ultra-high-energy cosmic
ray spectrum is very hard to measure experimentally, and to this day it remains
mostly unknown. Since the trajectories of ultra-high-energy cosmic rays are
deflected in the magnetic field of the Galaxy by an angle that depends on their
atomic number $Z$, it could be possible to indirectly measure $Z$ by
quantifying the amount of such magnetic deflections. In this paper we show
that, using the angular harmonic cross-correlation between ultra-high-energy
cosmic rays and galaxies, we could effectively distinguish different atomic
numbers with current data. As an example, we show how, if $Z=1$, the
cross-correlation can exclude a $39\%$ fraction of Fe56 nuclei at $2\sigma$ for
rays above $100\text{EeV}$.
- Weaker yet again: mass spectrum-consistent cosmological constraints on
the neutrino lifetime
2203.09075 [abs] [pdf]
[abstract]
by Joe Zhiyu Chen, [and 3 more]Isabel M. Oldengott, Giovanni Pierobon, and Yvonne Y. Y. Wong [hide authors].
We consider invisible neutrino decay $\nu_H \to \nu_l + \phi$ in the
ultra-relativistic limit and compute the neutrino anisotropy loss rate relevant
for the cosmic microwave background (CMB) anisotropies. Improving on our
previous work which assumed massless $\nu_l$ and $\phi$, we reinstate in this
work the daughter neutrino mass $m_{\nu l}$ in a manner consistent with the
experimentally determined neutrino mass splittings. We find that a nonzero
$m_{\nu l}$ introduces a new phase space factor in the loss rate $\Gamma_{\rm
T}$ proportional to $(\Delta m_\nu^2/m_{\nu_H}^2)^2$ in the limit of a small
squared mass gap between the parent and daughter neutrinos, i.e., $\Gamma_{\rm
T} \sim (\Delta m_\nu^2/m_{\nu H}^2)^2 (m_{\nu H}/E_\nu )^5 (1/\tau_0)$, where
$\tau_0$ is the $\nu_H$ rest-frame lifetime. Using a general form of this
result, we update the limit on $\tau_0$ using the Planck 2018 CMB data. We find
that for a parent neutrino of mass $m_{\nu H} \lesssim 0.1 {\rm eV}$, the new
phase space factor weakens the constraint on its lifetime by up to a factor of
50 if $\Delta m_\nu^2$ corresponds to the atmospheric mass gap and up to
$10^{5}$ if the solar mass gap, in comparison with naive estimates that assume
$m_{\nu l}=0$. The revised constraints are (i) $\tau^0 \gtrsim (6 \to 10)
\times 10^5~{\rm s}$ and $\tau^0 \gtrsim (400 \to 500)~{\rm s}$ if only one
neutrino decays to a daughter neutrino separated by, respectively, the
atmospheric and the solar mass gap, and (ii) $\tau^0 \gtrsim (2 \to 3) \times
10^7~{\rm s}$ in the case of two decay channels with one near-common
atmospheric mass gap. In contrast to previous, naive limits which scale as
$m_{\nu H}^5$, these mass spectrum-consistent $\tau_0$ constraints are
remarkably independent of the parent mass and open up a swath of parameter
space within the projected reach of IceCube and other neutrino telescopes in
the next two decades.
- Tau Neutrinos in the Next Decade: from GeV to EeV
2203.05591 [abs] [pdf]
[abstract]
by Roshan Mammen Abraham, [and 65 more]Jaime Alvarez-Muñiz, Carlos A. Argüelles, Akitaka Ariga, Tomoko Ariga, Adam Aurisano, Dario Autiero, Mary Bishai, Nilay Bostan, Mauricio Bustamante, Austin Cummings, Valentin Decoene, André de Gouvêa, Giovanni De Lellis, Albert De Roeck, Peter B. Denton, Antonia Di Crescenzo, Milind V. Diwan, Yasaman Farzan, Anatoli Fedynitch, Jonathan L. Feng, Laura J. Fields, Alfonso Garcia, Maria Vittoria Garzelli, Julia Gehrlein, Christian Glaser, Katarzyna Grzelak, Steffen Hallmann, V Hewes, D. Indumathi, Ahmed Ismail, Sudip Jana, Yu Seon Jeong, Kevin J. Kelly, Spencer R. Klein, Felix Kling, Thomas Kosc, Umut Kose, D. Jason Koskinen, John Krizmanic, Jeff Lazar, Yichen Li, Ivan Martinez-Soler, Irina Mocioiu, Jiwoo Nam, Valentin Niess, Nepomuk Otte, Sameer Patel, Roberto Petti, Remy L. Prechelt, Steven Prohira, Miriama Rajaoalisoa, Mary Hall Reno, Ibrahim Safa, Carlos Sarasty-Segura, R. Thiru Senthil, Juliana Stachurska, Oleksandr Tomalak, Sebastian Trojanowski, Roger Alexandre Wendell, Dawn Williams, Stephanie Wissel, Barbara Yaeggy, Enrique Zas, Pavel Zhelnin, and Jing-yu Zhu [hide authors].
Tau neutrinos are the least studied particle in the Standard Model. This
whitepaper discusses the current and expected upcoming status of tau neutrino
physics with attention to the broad experimental and theoretical landscape
spanning long-baseline, beam-dump, collider, and astrophysical experiments.
This whitepaper was prepared as a part of the NuTau2021 Workshop.
- Consequences of the Dresden-II reactor data for the weak mixing angle
and new physics
2203.02414 [abs] [pdf]
[abstract]
by D. Aristizabal Sierra, V. De Romeri, and D. K. Papoulias.
The Dresden-II reactor experiment has recently reported a suggestive evidence
for the observation of coherent elastic neutrino-nucleus scattering, using a
germanium detector. Given the low recoil energy threshold, these data are
particularly interesting for a low-energy determination of the weak mixing
angle and for the study of new physics leading to spectral distortions at low
momentum transfer. Using two hypotheses for the quenching factor, we study the
impact of the data on: (i) The weak mixing angle at a renormalization scale of
$\sim 10\,\text{MeV}$, (ii) neutrino generalized interactions with light
mediators, (iii) the sterile neutrino dipole portal. The results for the weak
mixing angle show a strong dependence on the quenching factor choice. Although
still with large uncertainties, the Dresden-II data provide for the first time
a determination of $\sin^2\theta_W$ at such scale using coherent elastic
neutrino-nucleus scattering data. Tight upper limits are placed on the light
vector, scalar and tensor mediator scenarios. Kinematic constraints implied by
the reactor anti-neutrino flux and the ionization energy threshold allow the
sterile neutrino dipole portal to produce up-scattering events with sterile
neutrino masses up to $\sim 8\,$MeV. In this context, we find that limits are
also sensitive to the quenching factor choice, but in both cases competitive
with those derived from XENON1T data and more stringent that those derived with
COHERENT data, in the same sterile neutrino mass range.
- Search for the Majorana Nature of Neutrinos in the Inverted Mass
Ordering Region with KamLAND-Zen
2203.02139 [abs] [pdf]
[abstract]
by KamLAND-Zen Collaboration, [and 74 more]:, S. Abe, S. Asami, M. Eizuka, S. Futagi, A. Gando, Y. Gando, T. Gima, A. Goto, T. Hachiya, K. Hata, S. Hayashida, K. Hosokawa, K. Ichimura, S. Ieki, H. Ikeda, K. Inoue, K. Ishidoshiro, Y. Kamei, N. Kawada, Y. Kishimoto, M. Koga, M. Kurasawa, N. Maemura, T. Mitsui, H. Miyake, T. Nakahata, K. Nakamura, K. Nakamura, R. Nakamura, H. Ozaki, T. Sakai, H. Sambonsugi, I. Shimizu, J. Shirai, K. Shiraishi, A. Suzuki, Y. Suzuki, A. Takeuchi, K. Tamae, K. Ueshima, H. Watanabe, Y. Yoshida, S. Obara, A. K. Ichikawa, D. Chernyak, A. Kozlov, K. Z. Nakamura, S. Yoshida, Y. Takemoto, S. Umehara, K. Fushimi, K. Kotera, Y. Urano, B. E. Berger, B. K. Fujikawa, J. G. Learned, J. Maricic, S. N. Axani, J. Smolsky, Z. Fu, L. A. Winslow, Y. Efremenko, H. J. Karwowski, D. M. Markoff, W. Tornow, S. Dell'Oro, T. O'Donnell, J. A. Detwiler, S. Enomoto, M. P. Decowski, C. Grant, A. Li, and H. Song [hide authors].
The KamLAND-Zen experiment has provided stringent constraints on the
neutrinoless double-beta ($0\nu\beta\beta$) decay half-life in $^{136}$Xe using
a xenon-loaded liquid scintillator. We report an improved search using an
upgraded detector with almost double the amount of xenon and an ultralow
radioactivity container, corresponding to an exposure of 970 kg yr of
$^{136}$Xe. These new data provide valuable insight into backgrounds,
especially from cosmic muon spallation of xenon, and have required the use of
novel background rejection techniques. We obtain a lower limit for the
$0\nu\beta\beta$ decay half-life of $T_{1/2}^{0\nu} > 2.3 \times 10^{26}$ yr at
90% C.L., corresponding to upper limits on the effective Majorana neutrino mass
of 36-156 meV using commonly adopted nuclear matrix element calculations.
February 2022
- An absolute $ν$ mass measurement with the DUNE experiment
2203.00024 [abs] [pdf]
[abstract]
by Federica Pompa, [and 3 more]Francesco Capozzi, Olga Mena, and Michel Sorel [hide authors].
Time of flight delay in the supernova neutrino signal offers a unique tool to
set model-independent constraints on the absolute neutrino mass. The presence
of a sharp time structure during a first emission phase, the so-called
neutronization burst in the electron neutrino flavor time distribution, makes
this channel a very powerful one. Large liquid argon underground detectors will
provide precision measurements of the time dependence of the electron neutrino
fluxes. We derive here a new $\nu$ mass sensitivity attainable at the future
DUNE far detector from a future supernova collapse in our galactic
neighborhood, finding a sub-eV reach under favorable scenarios. These values
are competitive with those expected for laboratory direct neutrino mass
searches.
- Theia: Summary of physics program. Snowmass White Paper Submission
2202.12839 [abs] [pdf]
[abstract]
by M. Askins, [and 86 more]Z. Bagdasarian, N. Barros, E. W. Beier, A. Bernstein, E. Blucher, R. Bonventre, E. Bourret, E. J. Callaghan, J. Caravaca, M. Diwan, S. T. Dye, J. Eisch, A. Elagin, T. Enqvist, U. Fahrendholz, V. Fischer, K. Frankiewicz, C. Grant, D. Guffanti, C. Hagner, A. Hallin, C. M. Jackson, R. Jiang, T. Kaptanoglu, J. R. Klein, Yu. G. Kolomensky, C. Kraus, F. Krennrich, T. Kutter, T. Lachenmaier, B. Land, K. Lande, L. Lebanowski, J. G. Learned, V. A. Li, V. Lozza, L. Ludhova, M. Malek, S. Manecki, J. Maneira, J. Maricic, J. Martyn, A. Mastbaum, C. Mauger, M. Mayer, J. Migenda, F. Moretti, J. Napolitano, B. Naranjo, M. Nieslony, L. Oberauer, G. D. Orebi Gann, J. Ouellet, T. Pershing, S. T. Petcov, L. Pickard, R. Rosero, M. C. Sanchez, J. Sawatzki, S. H. Seo, M. Smiley, M. Smy, A. Stahl, H. Steiger, M. R. Stock, H. Sunej, R. Svoboda, E. Tiras, W. H. Trzaska, M. Tzanov, M. Vagins, C. Vilela, Z. Wang, J. Wang, M. Wetstein, M. J. Wilking, L. Winslow, P. Wittich, B. Wonsak, E. Worcester, M. Wurm, G. Yang, M. Yeh, E. D. Zimmerman, S. Zsoldos, and K. Zuber [hide authors].
Theia would be a novel, "hybrid" optical neutrino detector, with a rich
physics program. This paper is intended to provide a brief overview of the
concepts and physics reach of Theia. Full details can be found in the Theia
white paper [1].
- Matter Effects of Sterile Neutrino in Light of Renormalization-Group
Equations
2202.09851 [abs] [pdf]
[abstract]
by Shuge Zeng and Fanrong Xu.
The renormalization-group equation (RGE) approach to neutrino matter effects
is further developed in this work. We derive a complete set of differential
equations for effective mixing elements, masses and Jarlskog-like invariants in
presence of a light sterile neutrino. The evolutions of mixing elements as well
as Jarlskog-like invariants are obtained by numerically solving these
differential equations. We calculate terrestrial matter effects in
long-baseline (LBL) experiments, taking NOvA, T2K and DUNE as examples. In both
three-flavor and four-flavor frameworks, electron-neutrino survival
probabilities as well as the day-night asymmetry of solar neutrino are also
evaluated as a further examination of the RGE approach.
- Improving CP Measurement with THEIA and Muon Decay at Rest
2202.05038 [abs] [pdf]
[abstract]
by Shao-Feng Ge, Chui-Fan Kong, and Pedro Pasquini.
We explore the possibility of using the recently proposed THEIA detector to
measure the $\bar \nu_\mu \rightarrow \bar \nu_e$ oscillation with neutrinos
from a muon decay at rest ($\mu$DAR) source to improve the leptonic CP phase
measurement. Due to its intrinsic low-energy beam, this $\mu$THEIA
configuration ($\mu$DAR neutrinos at THEIA) is only sensitive to the genuine
leptonic CP phase $\delta_D$ and not contaminated by the matter effect. With
detailed study of neutrino energy reconstruction and backgrounds at the THEIA
detector, we find that the combination with the high-energy DUNE can
significantly reduce the CP uncertainty, especially around the maximal CP
violation cases $\delta_D = \pm 90^\circ$. Both the $\mu$THEIA-25 with 17kt and
$\mu$THEIA-100 with 70kt fiducial volumes are considered. For DUNE +
$\mu$THEIA-100, the CP uncertainty can be better than $8^\circ$.
- Detecting Beyond the Standard Model Interactions of Solar Neutrinos in
Low-Threshold Dark Matter Detectors
2202.01254 [abs] [pdf]
[abstract]
by Thomas Schwemberger and Tien-Tien Yu.
As low-threshold dark matter detectors advance in development, they will
become sensitive to recoils from solar neutrinos which opens up the possibility
to explore neutrino properties. We predict the enhancement of the event rate of
solar neutrino scattering from Beyond the Standard Model interactions in
low-threshold DM detectors, with a focus on silicon, germanium, gallium
arsenide, xenon, and argon-based detectors. We consider a set of general
neutrino interactions, which fall into five categories: the neutrino magnetic
moment as well as interactions mediated by four types of mediators (scalar,
pseudoscalar, vector, and axial vector), and consider coupling these mediators
to either quarks or electrons. Using these predictions, we place constraints on
the mass and couplings of each mediator and the neutrino magnetic moment from
current low-threshold detectors like SENSEI, Edelweiss, and SuperCDMS, as well
as projections relevant for future experiments such as DAMIC-M, Oscura, Darwin,
and ARGO. We find that such low-threshold detectors can improve current
constraints by up to two orders of magnitude for vector mediators and one order
of magnitude for scalar mediators.
January 2022
- Influence of cross-sectional uncertainty on sensitivity studies of DUNE
and T2HK experiments
2201.08040 [abs] [pdf]
[abstract]
by Ritu Devi, Jaydip Singh, and Baba Potukuchi.
The ultimate objectives of ongoing and upcoming neutrino experiments are the
precise measurement of neutrino mixing parameters and the confirmation of mass
hierarchy. The systematic inaccuracy in the cross-section models introduces
inaccuracy in the neutrino mixing parameters estimation. It is important to
secure a large decrease of uncertainties, particularly those relating to
cross-section, neutrino-nucleus interactions, and neutrino-energy
reconstruction, in order to achieve these ambitious goals. In this research
article, we use three alternative neutrino event generators, GENIE, NuWro, and
GiBUU, to analyze sensitivity studies of T2HK, DUNE, and combined sensitivity
of DUNE, and T2HK for mass hierarchy, CP violation, and octant degeneracy
caused by cross-section uncertainties. The cross-section models of these
generators are separate and independent.
- Can NSI affect non-local correlations in neutrino oscillations?
2201.05580 [abs] [pdf]
[abstract]
by Bhavna Yadav, [and 3 more]Trisha Sarkar, Khushboo Dixit, and Ashutosh Kumar Alok [hide authors].
Non-local correlations in entangled systems are usually captured by measures
such as Bell's inequality violation. It was recently shown that in neutrino
systems, a measure of non-local advantage of quantum coherence (NAQC) can be
considered as a stronger measure of non-local correlations as compared to the
Bell's inequality violation. In this work, we analyze the effects of non
standard interaction (NSI) on these measures in the context of two flavour
neutrino oscillations for DUNE, MINOS, T2K, KamLAND, JUNO and Daya Bay
experimental set-ups. We find that even in the presence of NSI, Bell's
inequality violation occurs in the entire energy range whereas the NAQC
violation is observed only in some specific energy range justifying the more
elementary feature of NAQC. Further, we find that NSI can enhance the violation
of NAQC and Bell's inequality parameter in the higher energy range of a given
experimental set-up; these enhancements being maximal for the KamLAND
experiment. However, the possible enhancement in the violation of the Bell's
inequality parameter over the standard model prediction can be up to 11%
whereas for NAQC it is 7%. Thus although NAQC is a comparatively stronger
witness of nonclassicality, it shows lesser sensitivity to NSI effects in
comparison to the Bell's inequality parameter.
- Impact of Wave Packet Separation in Low-Energy Sterile Neutrino Searches
2201.05108 [abs] [pdf]
[abstract]
by Carlos A. Argüelles, Toni Bertólez-Martínez, and Jordi Salvado.
Light sterile neutrinos have been motivated by anomalies observed in
short-baseline neutrino experiments.Among them, radioactive-source and reactor
experiments have provided evidence and constraints, respectively, for electron
neutrino disappearance compatible with an eV-scale neutrino. The results from
these observations are seemingly in conflict. This letter brings into focus the
assumption that the neutrino wave packet can be approximated as a plane wave,
which is adopted in all analyses of such experiments. We demonstrate that the
damping of oscillations, e.g., due to a finite wave packet size, solve the
tension between these electron-flavor observations and constraints.
- Constraining Light Mediators via Detection of Coherent Elastic Solar
Neutrino Nucleus Scattering
2201.05015 [abs] [pdf]
[abstract]
by Yu-Feng Li and Shuo-yu Xia.
Dark matter (DM) direct detection experiments are entering the multiple-ton
era and will be sensitive to the coherent elastic neutrino nucleus scattering
(CE$\nu$NS) of solar neutrinos, enabling the possibility to explore
contributions from new physics with light mediators at the low energy range. In
this paper we consider light mediator models (scalar, vector and axial vector)
and the corresponding contributions to the solar neutrino CE$\nu$NS process.
Motivated by the current status of new generation of DM direct detection
experiments and the future plan, we study the sensitivity of light mediators in
DM direct detection experiments of different nuclear targets and detector
techniques. The constraints from the latest $^8$B solar neutrino measurements
of XENON-1T are also derived. Finally, We show that the solar neutrino
CE$\nu$NS process can provide stringent limitation on the $ L_{\mu}-L_{\tau} $
model with the vector mediator mass below 100 MeV, covering the viable
parameter space of the solution to the $ (g-2)_{\mu}$ anomaly.
- Strong constraints on neutrino nonstandard interactions from TeV-scale
$ν_μ$ disappearance at IceCube
2201.03566 [abs] [pdf]
[abstract]
by IceCube Collaboration, [and 383 more]R. Abbasi, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, J. M. Alameddine, A. A. Alves Jr., N. M. Amin, K. Andeen, T. Anderson, G. Anton, C. Argüelles, Y. Ashida, S. Axani, X. Bai, A. Balagopal V., S. W. Barwick, B. Bastian, V. Basu, S. Baur, R. Bay, J. J. Beatty, K. -H. Becker, J. Becker Tjus, J. Beise, C. Bellenghi, S. Benda, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, G. Binder, D. Bindig, E. Blaufuss, S. Blot, M. Boddenberg, F. Bontempo, J. Borowka, S. Böser, O. Botner, J. Böttcher, E. Bourbeau, F. Bradascio, J. Braun, B. Brinson, S. Bron, J. Brostean-Kaiser, S. Browne, A. Burgman, R. T. Burley, R. S. Busse, M. A. Campana, E. G. Carnie-Bronca, C. Chen, Z. Chen, D. Chirkin, K. Choi, B. A. Clark, K. Clark, L. Classen, A. Coleman, G. H. Collin, J. M. Conrad, P. Coppin, P. Correa, D. F. Cowen, R. Cross, C. Dappen, P. Dave, C. De Clercq, J. J. DeLaunay, D. Delgado López, H. Dembinski, K. Deoskar, A. Desai, P. Desiati, K. D. de Vries, G. de Wasseige, M. de With, T. DeYoung, A. Diaz, J. C. Díaz-Vélez, M. Dittmer, H. Dujmovic, M. Dunkman, M. A. DuVernois, E. Dvorak, T. Ehrhardt, P. Eller, R. Engel, H. Erpenbeck, J. Evans, P. A. Evenson, K. L. Fan, A. R. Fazely, A. Fedynitch, N. Feigl, S. Fiedlschuster, A. T. Fienberg, K. Filimonov, C. Finley, L. Fischer, D. Fox, A. Franckowiak, E. Friedman, A. Fritz, P. Fürst, T. K. Gaisser, J. Gallagher, E. Ganster, A. Garcia, S. Garrappa, L. Gerhardt, A. Ghadimi, C. Glaser, T. Glauch, T. Glüsenkamp, J. G. Gonzalez, S. Goswami, D. Grant, T. Grégoire, S. Griswold, C. Günther, P. Gutjahr, C. Haack, A. Hallgren, R. Halliday, L. Halve, F. Halzen, M. Ha Minh, K. Hanson, J. Hardin, A. A. Harnisch, A. Haungs, D. Hebecker, K. Helbing, F. Henningsen, E. C. Hettinger, S. Hickford, J. Hignight, C. Hill, G. C. Hill, K. D. Hoffman, R. Hoffmann, K. Hoshina, F. Huang, M. Huber, T. Huber, K. Hultqvist, M. Hünnefeld, R. Hussain, K. Hymon, S. In, N. Iovine, A. Ishihara, M. Jansson, G. S. Japaridze, M. Jeong, M. Jin, B. J. P. Jones, D. Kang, W. Kang, X. Kang, A. Kappes, D. Kappesser, L. Kardum, T. Karg, M. Karl, A. Karle, U. Katz, M. Kauer, M. Kellermann, J. L. Kelley, A. Kheirandish, K. Kin, T. Kintscher, J. Kiryluk, S. R. Klein, R. Koirala, H. Kolanoski, T. Kontrimas, L. Köpke, C. Kopper, S. Kopper, D. J. Koskinen, P. Koundal, M. Kovacevich, M. Kowalski, T. Kozynets, E. Kun, N. Kurahashi, N. Lad, C. Lagunas Gualda, J. L. Lanfranchi, M. J. Larson, F. Lauber, J. P. Lazar, J. W. Lee, K. Leonard, A. Leszczyńska, Y. Li, M. Lincetto, Q. R. Liu, M. Liubarska, E. Lohfink, C. J. Lozano Mariscal, L. Lu, F. Lucarelli, A. Ludwig, W. Luszczak, Y. Lyu, W. Y. Ma, J. Madsen, K. B. M. Mahn, Y. Makino, S. Mancina, I. C. Mari{ş}, I. Martinez-Soler, R. Maruyama, S. McCarthy, T. McElroy, F. McNally, J. V. Mead, K. Meagher, S. Mechbal, A. Medina, M. Meier, S. Meighen-Berger, J. Micallef, D. Mockler, T. Montaruli, R. W. Moore, R. Morse, M. Moulai, R. Naab, R. Nagai, U. Naumann, J. Necker, L. V. Nguy{\~{ê}}n, H. Niederhausen, M. U. Nisa, S. C. Nowicki, A. Obertacke Pollmann, M. Oehler, B. Oeyen, A. Olivas, E. O'Sullivan, H. Pandya, D. V. Pankova, N. Park, G. K. Parker, E. N. Paudel, L. Paul, C. Pérez de los Heros, L. Peters, J. Peterson, S. Philippen, S. Pieper, M. Pittermann, A. Pizzuto, M. Plum, Y. Popovych, A. Porcelli, M. Prado Rodriguez, B. Pries, G. T. Przybylski, C. Raab, J. Rack-Helleis, A. Raissi, M. Rameez, K. Rawlins, I. C. Rea, Z. Rechav, A. Rehman, P. Reichherzer, R. Reimann, G. Renzi, E. Resconi, S. Reusch, W. Rhode, M. Richman, B. Riedel, E. J. Roberts, S. Robertson, G. Roellinghoff, M. Rongen, C. Rott, T. Ruhe, D. Ryckbosch, D. Rysewyk Cantu, I. Safa, J. Saffer, S. E. Sanchez Herrera, A. Sandrock, M. Santander, S. Sarkar, S. Sarkar, K. Satalecka, M. Schaufel, H. Schieler, S. Schindler, T. Schmidt, A. Schneider, J. Schneider, F. G. Schröder, L. Schumacher, G. Schwefer, S. Sclafani, D. Seckel, S. Seunarine, A. Sharma, S. Shefali, N. Shimizu, M. Silva, B. Skrzypek, B. Smithers, R. Snihur, J. Soedingrekso, D. Soldin, C. Spannfellner, G. M. Spiczak, C. Spiering, J. Stachurska, M. Stamatikos, T. Stanev, R. Stein, J. Stettner, T. Stezelberger, T. Stürwald, T. Stuttard, G. W. Sullivan, I. Taboada, S. Ter-Antonyan, J. Thwaites, S. Tilav, F. Tischbein, K. Tollefson, C. Tönnis, S. Toscano, D. Tosi, A. Trettin, M. Tselengidou, C. F. Tung, A. Turcati, R. Turcotte, C. F. Turley, J. P. Twagirayezu, B. Ty, M. A. Unland Elorrieta, N. Valtonen-Mattila, J. Vandenbroucke, N. van Eijndhoven, D. Vannerom, J. van Santen, J. Veitch-Michaelis, S. Verpoest, C. Walck, W. Wang, T. B. Watson, C. Weaver, P. Weigel, A. Weindl, M. J. Weiss, J. Weldert, C. Wendt, J. Werthebach, M. Weyrauch, N. Whitehorn, C. H. Wiebusch, D. R. Williams, M. Wolf, K. Woschnagg, G. Wrede, J. Wulff, X. W. Xu, J. P. Yanez, E. Yildizci, S. Yoshida, S. Yu, T. Yuan, Z. Zhang, and P. Zhelnin [hide authors].
We report a search for nonstandard neutrino interactions (NSI) using eight
years of TeV-scale atmospheric muon neutrino data from the IceCube Neutrino
Observatory. By reconstructing incident energies and zenith angles for
atmospheric neutrino events, this analysis presents unified confidence
intervals for the NSI parameter $\epsilon_{\mu \tau}$. The best-fit value is
consistent with no NSI at a p-value of 25.2%. With a 90% confidence interval of
$-0.0041 \leq \epsilon_{\mu \tau} \leq 0.0031$ along the real axis and similar
strength in the complex plane, this result is the strongest constraint on any
NSI parameter from any oscillation channel to date.
- MiniBooNE and MicroBooNE Combined Fit to a 3+1 Sterile Neutrino Scenario
2201.01724 [abs] [pdf]
[abstract]
by A. A. Aguilar-Arevalo, [and 38 more]B. C. Brown, J. M. Conrad, R. Dharmapalan, A. Diaz, Z. Djurcic, D. A. Finley, R. Ford, G. T. Garvey, S. Gollapinni, A. Hourlier, E. -C. Huang, N. W. Kamp, G. Karagiorgi, T. Katori, T. Kobilarcik, K. Lin, W. C. Louis, C. Mariani, W. Marsh, G. B. Mills, J. Mirabal-Martinez, C. D. Moore, R. H. Nelson, J. Nowak, Z. Pavlovic, H. Ray, B. P. Roe, A. D. Russell, A. Schneider, M. H. Shaevitz, J. Spitz, I. Stancu, R. Tayloe, R. T. Thornton, M. Tzanov, R. G. Van de Water, D. H. White, and E. D. Zimmerman [hide authors].
This letter presents the results from the MiniBooNE experiment within a full
"3+1" scenario where one sterile neutrino is introduced to the
three-active-neutrino picture. In addition to electron-neutrino appearance at
short-baselines, this scenario also allows for disappearance of the
muon-neutrino and electron-neutrino fluxes in the Booster Neutrino Beam, which
is shared by the MicroBooNE experiment. We present the 3+1 fit to the MiniBooNE
electron-(anti)neutrino and muon-(anti)neutrino data alone, and in combination
with MicroBooNE electron-neutrino data. The best-fit parameters of the combined
fit with the exclusive CCQE analysis (inclusive analysis) are $\Delta m^2 =
0.29 eV^2 (0.33 eV^2)$, $|U_{e4}|^2 = 0.016 (0.500)$, $|U_{\mu 4}|^2 = 0.500
(0.500)$, and $\sin^2(2\theta_{\mu e})=0.0316 (1.0)$. Comparing the
no-oscillation scenario to the 3+1 model, the data prefer the 3+1 model with a
$\Delta \chi^2/\text{dof} = 24.7 / 3 (17.3 / 3)$, a $4.3\sigma (3.4\sigma)$
preference assuming the asymptotic approximation given by Wilks' theorem.
December 2021
- Search for non-standard neutrino interactions with 10 years of ANTARES
data
2112.14517 [abs] [pdf]
[abstract]
by A. Albert, [and 147 more]S. Alves, M. André, M. Anghinolfi, G. Anton, M. Ardid, S. Ardid, J. -J. Aubert, J. Aublin, B. Baret, S. Basa, B. Belhorma, M. Bendahman, F. Benfenati, V. Bertin, S. Biagi, M. Bissinger, J. Boumaaza, M. Bouta, M. C. Bouwhuis, H. Brânzas, R. Bruijn, J. Brunner, J. Busto, B. Caiffi, D. Calvo, A. Capone, L. Caramete, J. Carr, V. Carretero, S. Celli, M. Chabab, T. N. Chau, R. Cherkaoui El Moursli, T. Chiarusi, M. Circella, A. Coleiro, R. Coniglione, P. Coyle, A. Creusot, A. F. Díaz, G. de Wasseige, C. Distefano, I. Di Palma, A. Domi, C. Donzaud, D. Dornic, D. Drouhin, T. Eberl, T. van Eeden, D. van Eijk, N. El Khayati, A. Enzenhöfer, P. Fermani, G. Ferrara, F. Filippini, L. Fusco, Y. Gatelet, P. Gay, H. Glotin, R. Gozzini, R. Gracia Ruiz, K. Graf, C. Guidi, S. Hallmann, H. van Haren, A. J. Heijboer, Y. Hello, J. J. Hernández-Rey, J. Hößl, J. Hofestädt, F. Huang, G. Illuminati, C. W. James, B. Jisse-Jung, M. de Jong, P. de Jong, M. Kadler, O. Kalekin, U. Katz, N. R. Khan-Chowdhury, A. Kouchner, I. Kreykenbohm, V. Kulikovskiy, R. Lahmann, R. Le Breton, S. LeStum, D. Lefèvre, E. Leonora, G. Levi, M. Lincetto, D. Lopez-Coto, S. Loucatos, L. Maderer, J. Manczak, M. Marcelin, A. Margiotta, A. Marinelli, J. A. Martínez-Mora, B. Martino, K. Melis, P. Migliozzi, A. Moussa, R. Muller, L. Nauta, S. Navas, E. Nezri, B. Ó Fearraigh, A. Paun, G. E. Pavalas, C. Pellegrino, M. Perrin-Terrin, V. Pestel, P. Piattelli, C. Pieterse, C. Poirè, V. Popa, T. Pradier, N. Randazzo, D. Real, S. Reck, G. Riccobene, A. Romanov, A. Sánchez-Losa, F. Salesa Greus, D. F. E. Samtleben, M. Sanguineti, P. Sapienza, J. Schnabel, J. Schumann, F. Schüssler, J. Seneca, M. Spurio, Th. Stolarczyk, M. Taiuti, Y. Tayalati, T. Thakore, S. J. Tingay, B. Vallage, V. Van Elewyck, F. Versari, S. Viola, D. Vivolo, J. Wilms, S. Zavatarelli, A. Zegarelli, J. D. Zornoza, and J. Zúñiga [hide authors].
Non-standard interactions of neutrinos arising in many theories beyond the
Standard Model can significantly alter matter effects in atmospheric neutrino
propagation through the Earth. In this paper, a search for deviations from the
prediction of the standard 3-flavour atmospheric neutrino oscillations using
the data taken by the ANTARES neutrino telescope is presented. Ten years of
atmospheric neutrino data collected from 2007 to 2016, with reconstructed
energies in the range from $\sim$16 GeV to $100$ GeV, have been analysed. A
log-likelihood ratio test of the dimensionless coefficients
$\varepsilon_{\mu\tau}$ and $\varepsilon_{\tau\tau} - \varepsilon_{\mu\mu}$
does not provide clear evidence of deviations from standard interactions. For
normal neutrino mass ordering, the combined fit of both coefficients yields a
value 1.7$\sigma$ away from the null result. However, the 68% and 95%
confidence level intervals for $\varepsilon_{\mu\tau}$ and
$\varepsilon_{\tau\tau} - \varepsilon_{\mu\mu}$, respectively, contain the null
value. Best fit values, one standard deviation errors and bounds at the 90%
confidence level for these coefficients are given for both normal and inverted
mass orderings. The constraint on $\varepsilon_{\mu\tau}$ is among the most
stringent to date and it further restrains the strength of possible
non-standard interactions in the $\mu - \tau$ sector.
- Damping signatures at JUNO, a medium-baseline reactor neutrino
oscillation experiment
2112.14450 [abs] [pdf]
[abstract]
by JUNO collaboration, [and 606 more]Jun Wang, Jiajun Liao, Wei Wang, Angel Abusleme, Thomas Adam, Shakeel Ahmad, Rizwan Ahmed, Sebastiano Aiello, Muhammad Akram, Fengpeng An, Qi An, Giuseppe Andronico, Nikolay Anfimov, Vito Antonelli, Tatiana Antoshkina, Burin Asavapibhop, João Pedro Athayde Marcondes de André, Didier Auguste, Andrej Babic, Nikita Balashov, Wander Baldini, Andrea Barresi, Davide Basilico, Eric Baussan, Marco Bellato, Antonio Bergnoli, Thilo Birkenfeld, Sylvie Blin, David Blum, Simon Blyth, Anastasia Bolshakova, Mathieu Bongrand, Clément Bordereau, Dominique Breton, Augusto Brigatti, Riccardo Brugnera, Riccardo Bruno, Antonio Budano, Mario Buscemi, Jose Busto, Ilya Butorov, Anatael Cabrera, Hao Cai, Xiao Cai, Yanke Cai, Zhiyan Cai, Riccardo Callegari, Antonio Cammi, Agustin Campeny, Chuanya Cao, Guofu Cao, Jun Cao, Rossella Caruso, Cédric Cerna, Jinfan Chang, Yun Chang, Pingping Chen, Po-An Chen, Shaomin Chen, Xurong Chen, Yi-Wen Chen, Yixue Chen, Yu Chen, Zhang Chen, Jie Cheng, Yaping Cheng, Alexey Chetverikov, Davide Chiesa, Pietro Chimenti, Artem Chukanov, Gérard Claverie, Catia Clementi, Barbara Clerbaux, Selma Conforti Di Lorenzo, Daniele Corti, Flavio Dal Corso, Olivia Dalager, Christophe De La Taille, Jiawei Deng, Zhi Deng, Ziyan Deng, Wilfried Depnering, Marco Diaz, Xuefeng Ding, Yayun Ding, Bayu Dirgantara, Sergey Dmitrievsky, Tadeas Dohnal, Dmitry Dolzhikov, Georgy Donchenko, Jianmeng Dong, Evgeny Doroshkevich, Marcos Dracos, Frédéric Druillole, Ran Du, Shuxian Du, Stefano Dusini, Martin Dvorak, Timo Enqvist, Heike Enzmann, Andrea Fabbri, Lukas Fajt, Donghua Fan, Lei Fan, Jian Fang, Wenxing Fang, Marco Fargetta, Dmitry Fedoseev, Vladko Fekete, Li-Cheng Feng, Qichun Feng, Richard Ford, Amélie Fournier, Haonan Gan, Feng Gao, Alberto Garfagnini, Arsenii Gavrikov, Marco Giammarchi, Agnese Giaz, Nunzio Giudice, Maxim Gonchar, Guanghua Gong, Hui Gong, Yuri Gornushkin, Alexandre Göttel, Marco Grassi, Christian Grewing, Vasily Gromov, Minghao Gu, Xiaofei Gu, Yu Gu, Mengyun Guan, Nunzio Guardone, Maria Gul, Cong Guo, Jingyuan Guo, Wanlei Guo, Xinheng Guo, Yuhang Guo, Paul Hackspacher, Caren Hagner, Ran Han, Yang Han, Muhammad Sohaib Hassan, Miao He, Wei He, Tobias Heinz, Patrick Hellmuth, Yuekun Heng, Rafael Herrera, YuenKeung Hor, Shaojing Hou, Yee Hsiung, Bei-Zhen Hu, Hang Hu, Jianrun Hu, Jun Hu, Shouyang Hu, Tao Hu, Zhuojun Hu, Chunhao Huang, Guihong Huang, Hanxiong Huang, Wenhao Huang, Xin Huang, Xingtao Huang, Yongbo Huang, Jiaqi Hui, Lei Huo, Wenju Huo, Cédric Huss, Safeer Hussain, Ara Ioannisian, Roberto Isocrate, Beatrice Jelmini, Kuo-Lun Jen, Ignacio Jeria, Xiaolu Ji, Xingzhao Ji, Huihui Jia, Junji Jia, Siyu Jian, Di Jiang, Wei Jiang, Xiaoshan Jiang, Ruyi Jin, Xiaoping Jing, Cécile Jollet, Jari Joutsenvaara, Sirichok Jungthawan, Leonidas Kalousis, Philipp Kampmann, Li Kang, Rebin Karaparambil, Narine Kazarian, Khanchai Khosonthongkee, Denis Korablev, Konstantin Kouzakov, Alexey Krasnoperov, Andre Kruth, Nikolay Kutovskiy, Pasi Kuusiniemi, Tobias Lachenmaier, Cecilia Landini, Sébastien Leblanc, Victor Lebrin, Frederic Lefevre, Ruiting Lei, Rupert Leitner, Jason Leung, Demin Li, Fei Li, Fule Li, Haitao Li, Huiling Li, Jiaqi Li, Mengzhao Li, Min Li, Nan Li, Nan Li, Qingjiang Li, Ruhui Li, Shanfeng Li, Tao Li, Weidong Li, Weiguo Li, Xiaomei Li, Xiaonan Li, Xinglong Li, Yi Li, Yufeng Li, Zhaohan Li, Zhibing Li, Ziyuan Li, Hao Liang, Hao Liang, Daniel Liebau, Ayut Limphirat, Sukit Limpijumnong, Guey-Lin Lin, Shengxin Lin, Tao Lin, Jiajie Ling, Ivano Lippi, Fang Liu, Haidong Liu, Hongbang Liu, Hongjuan Liu, Hongtao Liu, Hui Liu, Jianglai Liu, Jinchang Liu, Min Liu, Qian Liu, Qin Liu, Runxuan Liu, Shuangyu Liu, Shubin Liu, Shulin Liu, Xiaowei Liu, Xiwen Liu, Yan Liu, Yunzhe Liu, Alexey Lokhov, Paolo Lombardi, Claudio Lombardo, Kai Loo, Chuan Lu, Haoqi Lu, Jingbin Lu, Junguang Lu, Shuxiang Lu, Xiaoxu Lu, Bayarto Lubsandorzhiev, Sultim Lubsandorzhiev, Livia Ludhova, Arslan Lukanov, Fengjiao Luo, Guang Luo, Pengwei Luo, Shu Luo, Wuming Luo, Vladimir Lyashuk, Bangzheng Ma, Qiumei Ma, Si Ma, Xiaoyan Ma, Xubo Ma, Jihane Maalmi, Yury Malyshkin, Roberto Carlos Mandujano, Fabio Mantovani, Francesco Manzali, Xin Mao, Yajun Mao, Stefano M. Mari, Filippo Marini, Sadia Marium, Cristina Martellini, Gisele Martin-Chassard, Agnese Martini, Matthias Mayer, Davit Mayilyan, Ints Mednieks, Yue Meng, Anselmo Meregaglia, Emanuela Meroni, David Meyhöfer, Mauro Mezzetto, Jonathan Miller, Lino Miramonti, Paolo Montini, Michele Montuschi, Axel Müller, Massimiliano Nastasi, Dmitry V. Naumov, Elena Naumova, Diana Navas-Nicolas, Igor Nemchenok, Minh Thuan Nguyen Thi, Feipeng Ning, Zhe Ning, Hiroshi Nunokawa, Lothar Oberauer, Juan Pedro Ochoa-Ricoux, Alexander Olshevskiy, Domizia Orestano, Fausto Ortica, Rainer Othegraven, Hsiao-Ru Pan, Alessandro Paoloni, Sergio Parmeggiano, Yatian Pei, Nicomede Pelliccia, Anguo Peng, Haiping Peng, Frédéric Perrot, Pierre-Alexandre Petitjean, Fabrizio Petrucci, Oliver Pilarczyk, Luis Felipe Piñeres Rico, Artyom Popov, Pascal Poussot, Wathan Pratumwan, Ezio Previtali, Fazhi Qi, Ming Qi, Sen Qian, Xiaohui Qian, Zhen Qian, Hao Qiao, Zhonghua Qin, Shoukang Qiu, Muhammad Usman Rajput, Gioacchino Ranucci, Neill Raper, Alessandra Re, Henning Rebber, Abdel Rebii, Bin Ren, Jie Ren, Barbara Ricci, Markus Robens, Mathieu Roche, Narongkiat Rodphai, Aldo Romani, Bedřich Roskovec, Christian Roth, Xiangdong Ruan, Xichao Ruan, Saroj Rujirawat, Arseniy Rybnikov, Andrey Sadovsky, Paolo Saggese, Simone Sanfilippo, Anut Sangka, Nuanwan Sanguansak, Utane Sawangwit, Julia Sawatzki, Fatma Sawy, Michaela Schever, Cédric Schwab, Konstantin Schweizer, Alexandr Selyunin, Andrea Serafini, Giulio Settanta, Mariangela Settimo, Zhuang Shao, Vladislav Sharov, Arina Shaydurova, Jingyan Shi, Yanan Shi, Vitaly Shutov, Andrey Sidorenkov, Fedor Šimkovic, Chiara Sirignano, Jaruchit Siripak, Monica Sisti, Maciej Slupecki, Mikhail Smirnov, Oleg Smirnov, Thiago Sogo-Bezerra, Sergey Sokolov, Julanan Songwadhana, Boonrucksar Soonthornthum, Albert Sotnikov, Ondřej Šrámek, Warintorn Sreethawong, Achim Stahl, Luca Stanco, Konstantin Stankevich, Dušan Štefánik, Hans Steiger, Jochen Steinmann, Tobias Sterr, Matthias Raphael Stock, Virginia Strati, Alexander Studenikin, Shifeng Sun, Xilei Sun, Yongjie Sun, Yongzhao Sun, Narumon Suwonjandee, Michal Szelezniak, Jian Tang, Qiang Tang, Quan Tang, Xiao Tang, Alexander Tietzsch, Igor Tkachev, Tomas Tmej, Marco Danilo Claudio Torri, Konstantin Treskov, Andrea Triossi, Giancarlo Troni, Wladyslaw Trzaska, Cristina Tuve, Nikita Ushakov, Johannes van den Boom, Stefan van Waasen, Guillaume Vanroyen, Vadim Vedin, Giuseppe Verde, Maxim Vialkov, Benoit Viaud, Cornelius Moritz Vollbrecht, Cristina Volpe, Vit Vorobel, Dmitriy Voronin, Lucia Votano, Pablo Walker, Caishen Wang, Chung-Hsiang Wang, En Wang, Guoli Wang, Jian Wang, Kunyu Wang, Lu Wang, Meifen Wang, Meng Wang, Meng Wang, Ruiguang Wang, Siguang Wang, Wei Wang, Wenshuai Wang, Xi Wang, Xiangyue Wang, Yangfu Wang, Yaoguang Wang, Yi Wang, Yi Wang, Yifang Wang, Yuanqing Wang, Yuman Wang, Zhe Wang, Zheng Wang, Zhimin Wang, Zongyi Wang, Muhammad Waqas, Apimook Watcharangkool, Lianghong Wei, Wei Wei, Wenlu Wei, Yadong Wei, Kaile Wen, Liangjian Wen, Christopher Wiebusch, Steven Chan-Fai Wong, Bjoern Wonsak, Diru Wu, Qun Wu, Zhi Wu, Michael Wurm, Jacques Wurtz, Christian Wysotzki, Yufei Xi, Dongmei Xia, Xiaochuan Xie, Yuguang Xie, Zhangquan Xie, Zhizhong Xing, Benda Xu, Cheng Xu, Donglian Xu, Fanrong Xu, Hangkun Xu, Jilei Xu, Jing Xu, Meihang Xu, Yin Xu, Yu Xu, Baojun Yan, Taylor Yan, Wenqi Yan, Xiongbo Yan, Yupeng Yan, Anbo Yang, Changgen Yang, Chengfeng Yang, Huan Yang, Jie Yang, Lei Yang, Xiaoyu Yang, Yifan Yang, Yifan Yang, Haifeng Yao, Zafar Yasin, Jiaxuan Ye, Mei Ye, Ziping Ye, Ugur Yegin, Frédéric Yermia, Peihuai Yi, Na Yin, Xiangwei Yin, Zhengyun You, Boxiang Yu, Chiye Yu, Chunxu Yu, Hongzhao Yu, Miao Yu, Xianghui Yu, Zeyuan Yu, Zezhong Yu, Chengzhuo Yuan, Ying Yuan, Zhenxiong Yuan, Ziyi Yuan, Baobiao Yue, Noman Zafar, Andre Zambanini, Vitalii Zavadskyi, Shan Zeng, Tingxuan Zeng, Yuda Zeng, Liang Zhan, Aiqiang Zhang, Feiyang Zhang, Guoqing Zhang, Haiqiong Zhang, Honghao Zhang, Jiawen Zhang, Jie Zhang, Jin Zhang, Jingbo Zhang, Jinnan Zhang, Peng Zhang, Qingmin Zhang, Shiqi Zhang, Shu Zhang, Tao Zhang, Xiaomei Zhang, Xuantong Zhang, Xueyao Zhang, Yan Zhang, Yinhong Zhang, Yiyu Zhang, Yongpeng Zhang, Yuanyuan Zhang, Yumei Zhang, Zhenyu Zhang, Zhijian Zhang, Fengyi Zhao, Jie Zhao, Rong Zhao, Shujun Zhao, Tianchi Zhao, Dongqin Zheng, Hua Zheng, Minshan Zheng, Yangheng Zheng, Weirong Zhong, Jing Zhou, Li Zhou, Nan Zhou, Shun Zhou, Tong Zhou, Xiang Zhou, Jiang Zhu, Kangfu Zhu, Kejun Zhu, Zhihang Zhu, Bo Zhuang, Honglin Zhuang, Liang Zong, and Jiaheng Zou [hide authors].
We study damping signatures at the Jiangmen Underground Neutrino Observatory
(JUNO), a medium-baseline reactor neutrino oscillation experiment. These
damping signatures are motivated by various new physics models, including
quantum decoherence, $\nu_3$ decay, neutrino absorption, and wave packet
decoherence. The phenomenological effects of these models can be characterized
by exponential damping factors at the probability level. We assess how well
JUNO can constrain these damping parameters and how to disentangle these
different damping signatures at JUNO. Compared to current experimental limits,
JUNO can significantly improve the limits on $\tau_3/m_3$ in the $\nu_3$ decay
model, the width of the neutrino wave packet $\sigma_x$, and the intrinsic
relative dispersion of neutrino momentum $\sigma_{\rm rel}$.
- Neutrino oscillations in Earth for probing dark matter inside the core
2112.14201 [abs] [pdf]
[abstract]
by Anuj Kumar Upadhyay, [and 3 more]Anil Kumar, Sanjib Kumar Agarwalla, and Amol Dighe [hide authors].
Atmospheric neutrinos offer the possibility of probing dark matter inside the
core of the Earth in a unique way, through Earth matter effects in neutrino
oscillations. For example, if dark matter constitutes 40% of the mass inside
the core, a detector like ICAL at INO with muon charge identification
capability can be sensitive to it at around 2$\sigma$ confidence level with
1000 kt$\cdot$yr exposure. We demonstrate that while the dark matter profile
will be hard to identify, the baryonic matter profile inside the core can be
probed in a manner complementary to the seismic measurements.
- Improved cosmological constraints on the neutrino mass and lifetime
2112.13862 [abs] [pdf]
[abstract]
by Guillermo F. Abellán, [and 5 more]Zackaria Chacko, Abhish Dev, Peizhi Du, Vivian Poulin, and Yuhsin Tsai [hide authors].
We present cosmological constraints on the sum of neutrino masses as a
function of the neutrino lifetime, in a framework in which neutrinos decay into
dark radiation after becoming non-relativistic. We find that in this regime the
cosmic microwave background (CMB), baryonic acoustic oscillations (BAO) and
(uncalibrated) luminosity distance to supernovae from the Pantheon catalog
constrain the sum of neutrino masses $\sum m_\nu$ to obey $\sum m_\nu< 0.42$ eV
at (95$\%$ C.L.). While the the bound has improved significantly as compared to
the limits on the same scenario from Planck 2015, it still represents a
significant relaxation of the constraints as compared to the stable neutrino
case. We show that most of the improvement can be traced to the more precise
measurements of low-$\ell$ polarization data in Planck 2018, which leads to
tighter constraints on $\tau_{\rm reio}$ (and thereby on $A_s$), breaking the
degeneracy arising from the effect of (large) neutrino masses on the amplitude
of the CMB power spectrum.
- Neutrino magnetic and electric dipole moments: From measurements to
parameter space
2112.12817 [abs] [pdf]
[abstract]
by D. Aristizabal Sierra, [and 3 more]O. G. Miranda, D. K. Papoulias, and G. Sanchez Garcia [hide authors].
Searches for neutrino magnetic moments/transitions in low energy neutrino
scattering experiments are sensitive to effective couplings which are an
intricate function of the Hamiltonian parameters. We study the parameter space
dependence of these couplings in the Majorana (transitions) and Dirac (moments)
cases, as well as the impact of the current most stringent experimental upper
limits on the fundamental parameters. In the Majorana case we find that for
reactor, short-baseline and solar neutrinos, CP violation can be understood as
a measurement of parameter space vectors misalignments. The presence of
nonvanishing CP phases opens a blind spot region where -- regardless of how
large the parameters are -- no signal can be observed in either reactor or
short-baseline experiments. Identification of these regions requires a
combination of different data sets and allows for the determination of those CP
phases. We point out that stringent bounds not necessarily imply suppressed
Hamiltonian couplings, thus allowing for regions where disparate upper limits
can be simultaneously satisfied. In contrast, in the Dirac case stringent
experimental upper limits necessarily translate into tight bounds on the
fundamental couplings. In terms of parameter space vectors, we provide a
straightforward mapping of experimental information into parameter space.
- Depletion of atmospheric neutrino fluxes from parton energy loss
2112.10791 [abs] [pdf]
[abstract]
by François Arleo, Greg Jackson, and Stéphane Peigné.
The phenomenon of fully coherent energy loss (FCEL) in the collisions of
protons on light ions affects the physics of cosmic ray air showers. As an
illustration, we address two closely related observables: hadron production in
forthcoming proton-oxygen collisions at the LHC, and the atmospheric neutrino
fluxes induced by the semileptonic decays of hadrons produced in proton-air
collisions. In both cases, a significant nuclear suppression due to FCEL is
predicted. The conventional and prompt neutrino fluxes are suppressed by $\sim
10...25\%$ in their relevant neutrino energy ranges. Previous estimates of
atmospheric neutrino fluxes should be scaled down accordingly to account for
FCEL.
- The Return of the Templates: Revisiting the Galactic Center Excess with
Multi-Messenger Observations
2112.09706 [abs] [pdf]
[abstract]
by Ilias Cholis, [and 3 more]Yi-Ming Zhong, Samuel D. McDermott, and Joseph P. Surdutovich [hide authors].
The Galactic center excess (GCE) remains one of the most intriguing
discoveries from the Fermi Large Area Telescope (LAT) observations. We revisit
the characteristics of the GCE by first producing a new set of high-resolution
galactic diffuse gamma-ray emission templates, which are ultimately due to
cosmic-ray interactions with the interstellar medium. Using multi-messenger
observations we constrain the properties of the galactic diffuse emission. The
broad properties of the GCE that we find in this work are qualitatively
unchanged despite the introduction of this new set of templates, though its
quantitative features appear mildly different than those obtained in previous
analyses. In particular, we find a high-energy tail at higher significance than
previously reported. This tail is very prominent in the northern hemisphere,
and less so in the southern hemisphere. This strongly affects one prominent
interpretation of the excess: known millisecond pulsars are incapable of
producing this high-energy emission, even in the relatively softer southern
hemisphere, and are therefore disfavored as the sole explanation of the GCE.
The annihilation of dark matter particles of mass $40^{+10}_{-7}$ GeV (95$\%$
CL) to $b$ quarks with a cross-section of $\sigma v = 1.4^{+0.6}_{-0.3} \times
10^{-26}$ cm$^{3}$s$^{-1}$ provides a good fit to the excess especially in the
relatively cleaner southern sky. Dark matter of the same mass range
annihilating to $b$ quarks or heavier dark matter particles annihilating to
heavier Standard Model bosons can combine with millisecond pulsars to provide a
good fit to the southern hemisphere emission. As part of this paper, we make
publicly available all of our templates and the data covariance matrix we have
generated to account for systematic uncertainties.[abridged]
- Probing New Physics at Future Tau Neutrino Telescopes
2112.09476 [abs] [pdf]
[abstract]
by Guo-yuan Huang, [and 3 more]Sudip Jana, Manfred Lindner, and Werner Rodejohann [hide authors].
We systematically investigate new physics scenarios that can modify the
interactions between neutrinos and matter at upcoming tau neutrino telescopes,
which will test neutrino-proton collisions with energies $ \gtrsim 45~{\rm
TeV}$, and can provide unique insights to the elusive tau neutrino. At such
high energy scales, the impact of parton distribution functions of second and
third generations of quarks (usually suppressed) can be comparable to the
contribution of first generation with small momentum fraction, hence making tau
neutrino telescopes an excellent facility to probe new physics associated with
second and third families. Among an inclusive set of particle physics models,
we identify new physics scenarios at tree level that can give competitive
contributions to the neutrino cross sections while staying within laboratory
constraints: charged/neutral Higgs and leptoquarks. Our analysis is close to
the actual experimental configurations of the telescopes, and we perform a
$\chi^2$-analysis on the energy and angular distributions of the tau events. By
numerically solving the propagation equations of neutrino and tau fluxes in
matter, we obtain the sensitivities of representative upcoming tau neutrino
telescopes, GRAND, POEMMA and Trinity, to the charged Higgs and leptoquark
models. While each of the experiments can achieve a sensitivity better than the
current collider reaches for certain models, their combination is remarkably
complementary in probing the new physics. In particular, the new physics will
affect the energy and angular distributions in different ways at those
telescopes.
- Towards Probing the Diffuse Supernova Neutrino Background in All Flavors
2112.09168 [abs] [pdf]
[abstract]
by Anna M. Suliga, John F. Beacom, and Irene Tamborra.
Fully understanding the average core-collapse supernova requires detecting
the diffuse supernova neutrino background (DSNB) in all flavors. While the DSNB
$\bar{\nu}_e$ flux is near detection, and the DSNB $\nu_e$ flux has a good
upper limit and prospects for improvement, the DSNB $\nu_x$ (each of $\nu_\mu,
\nu_\tau, \bar{\nu}_\mu, \bar{\nu}_\tau$) flux has a poor limit and heretofore
had no clear path for improved sensitivity. We show that a succession of
xenon-based dark matter detectors -- XENON1T (completed), XENONnT/LUX-ZEPLIN
(running), and DARWIN (proposed) -- can dramatically improve sensitivity to
DSNB $\nu_x$ the neutrino-nucleus coherent scattering channel. XENON1T could
match the present sensitivity of $\sim 10^3 \;
\mathrm{cm}^{-2}~\mathrm{s}^{-1}$ per $\nu_x$ flavor, XENONnT/LUX-ZEPLIN would
have linear improvement of sensitivity with exposure, and a long run of DARWIN
could reach a flux sensitivity of $\sim 10 \;
\mathrm{cm}^{-2}~\mathrm{s}^{-1}$. Together, these would also contribute to
greatly improve bounds on non-standard scenarios. Ultimately, to reach the
standard flux range of $\sim 1 \; \mathrm{cm}^{-2}~\mathrm{s}^{-1}$, even
larger exposures will be needed, which we show may be possible with the series
of proposed lead-based RES-NOVA detectors.
- On T violation in non-standard neutrino oscillation scenarios
2112.08801 [abs] [pdf]
[abstract]
by Thomas Schwetz and Alejandro Segarra.
We discuss time reversal (T) violation in neutrino oscillations in generic
new physics scenarios. A general parameterization is adopted to describe
flavour evolution, which captures a wide range of new physics effects,
including non-standard neutrino interactions, non-unitarity, and sterile
neutrinos in a model-independent way. In this framework, we discuss general
properties of time reversal in the context of long-baseline neutrino
experiments. Special attention is given to fundamental versus environmental T
violation in the presence of generic new physics. We point out that T violation
in the disappearance channel requires new physics which modifies flavour mixing
at neutrino production and detection. We use time-dependent perturbation theory
to study the effect of non-constant matter density along the neutrino path, and
quantify the effects for the well studied baselines of the DUNE, T2HK, and
T2HKK projects. The material presented here provides the phenomenological
background for the model-independent test of T violation proposed by us in Ref.
[1].
- Excess of Tau events at SND@LHC, FASER$ν$ and FASER$ν$2
2112.08799 [abs] [pdf]
[abstract]
by Saeed Ansarifard and Yasaman Farzan.
During the run III of the LHC, the forward experiments FASER$\nu$ and SND@LHC
will be able to detect the Charged Current (CC) interactions of the high energy
neutrinos of all three flavors produced at the ATLAS Interaction Point (IP).
This opportunity may unravel mysteries of the third generation leptons. We
build three models that can lead to a tau excess at these detectors through the
following Lepton Flavor Violating (LFV) beyond Standard Model (SM) processes:
(1) $\pi^+ \to \mu^+ \nu_\tau$; (2) $\pi^+ \to \mu^+ \bar{\nu}_\tau$ and (3)
$\nu_e+{\rm nucleus}\to \tau +X$. We comment on the possibility of solving the
$(g-2)_\mu$ anomaly and the $\tau$ decay anomalies within these models. We
study the potential of the forward experiments to discover the $\tau$ excess or
to constrain these models in case of no excess. We then compare the reach of
the forward experiments with that of the previous as well as next generation
experiments such as DUNE. We also discuss how the upgrade of FASER$\nu$ can
distinguish between these models by studying the energy spectrum of the tau.
- Tau Appearance from High-Energy Neutrino Interactions
2112.06937 [abs] [pdf]
[abstract]
by Alfonso Garcia Soto, [and 3 more]Pavel Zhelnin, Ibrahim Safa, and Carlos A. Argüelles [hide authors].
High-energy muon- and electron-neutrinos yield a non-negligible flux of tau
neutrinos as they propagate through Earth. In this letter, we address the
impact of this additional component in the PeV and EeV energy regimes for the
first time. This contribution is predicted to be significantly larger than the
atmospheric background above 300 TeV, and alters current and future neutrino
telescopes' capabilities to discover a cosmic tau-neutrino flux. Further we
demonstrate that Earthskimming neutrino experiments, designed to observe tau
neutrinos, will be sensitive to cosmogenic neutrinos even in extreme scenarios
without a primary tau-neutrino component.
- Toward diagnosing neutrino non-unitarity through CP phase correlations
2112.06178 [abs] [pdf]
[abstract]
by Hisakazu Minakata.
We discuss correlations between the $\nu$SM CP phase $\delta$ and the phases
that originate from new physics which causes neutrino-sector unitarity
violation (UV) at low energies. This study is motivated to provide one of the
building pieces for a machinery to diagnose non-unitarity, our ultimate goal.
We extend the perturbation theory of neutrino oscillation in matter proposed by
Denton {\it et al.}~(DMP) to include the UV effect expressed by the $\alpha$
parametrization. By analyzing the DMP-UV perturbation theory to first order, we
are able to draw a completed picture of the $\delta$ - UV phase correlations in
the whole kinematical region covered by the terrestrial neutrino experiments.
There exist the two regions with the characteristically different patterns of
the correlations: (1) the chiral-type $[e^{- i \delta } \alpha_{\mu e}, ~e^{ -
i \delta} \alpha_{\tau e}, ~\alpha_{\tau \mu}]$ (PDG convention) correlation in
the entire high-energy region $\vert \rho E \vert \gsim 6~(\text{g/cm}^3)$ GeV,
and (2) (blobs of the $\alpha$ parameters) - $e^{ \pm i \delta}$ correlation in
anywhere else. Some relevant aspects for measurement of the UV parameters, such
as the necessity of determining all the $\alpha_{\beta \gamma}$ elements at
once, are also pointed out.
- Neutrino Transition in Dark Matter
2112.05057 [abs] [pdf]
[abstract]
by Eung Jin Chun.
An ultralight dark matter may have interesting implications in neutrino
physics which have been studied actively in recent years. It is pointed out
that there appears yet unexplored medium effect in neutrino transitions which
occurs at the first order in perturbation of the neutrino-medium interaction.
We derive the general formula for the neutrino transition probability in a
medium which describes the standard neutrino oscillation as well as the new
medium contribution. It turns out that such an effect constrains the model
parameter space more than ever.
- Neutrino Mass Bounds in the era of Tension Cosmology
2112.02993 [abs] [pdf]
[abstract]
by Eleonora Di Valentino and Alessandro Melchiorri.
The measurements of Cosmic Microwave Background anisotropies made by the
Planck satellite provide extremely tight upper bounds on the total neutrino
mass scale ($\Sigma m_{\nu}<0.26 eV$ at $95\%$ C.L.). However, as recently
discussed in the literature, Planck data show anomalies that could affect this
result. Here we provide new constraints on neutrino masses using the recent and
complementary CMB measurements from the Atacama Cosmology Telescope DR4 and the
South Polar Telescope SPT-3G experiments. We found that both the ACT-DR4 and
SPT-3G data, when combined with WMAP, mildly suggest a neutrino mass with
$\Sigma m_{\nu}=0.68 \pm 0.31$ eV and $\Sigma m_{\nu}=0.46_{-0.36}^{+0.14}$ eV
at $68 \%$ C.L, respectively. Moreover, when CMB lensing from the Planck
experiment is included, the ACT-DR4 data now indicates a neutrino mass above
the two standard deviations, with $\Sigma m_{\nu}=0.60_{-0.50}^{+0.44}$ eV at
$95 \%$, while WMAP+SPT-3G provides a weak upper limit of $\Sigma m_{\nu}<0.37$
eV at $68 \%$ C.L.. Interestingly, these results are consistent with the Planck
CMB+Lensing constraint of $\Sigma m_{\nu} = 0.41_{-0.25}^{+0.17}$ eV at $68 \%$
C.L. when variation in the $A_{\rm lens}$ parameter are considered. We also
show that these indications are still present after the inclusion of BAO or
SN-Ia data in extended cosmologies that are usually considered to solve the
so-called Hubble tension. A combination of ACT-DR4, WMAP, BAO and constraints
on the Hubble constant from the SH0ES collaboration gives $\Sigma
m_{\nu}=0.39^{+0.13}_{-0.25}$ eV at $68 \%$ C.L. in extended cosmologies. We
conclude that a total neutrino mass above the $0.26$ eV limit still provides an
excellent fit to several cosmological data and that future data must be
considered before safely ruling it out.
- Time- and Space-Varying Neutrino Mass Matrix from Soft Topological
Defects
2112.02107 [abs] [pdf]
[abstract]
by Gia Dvali, Lena Funcke, and Tanmay Vachaspati.
We study the formation and evolution of topological defects that arise in the
post-recombination phase transition predicted by the gravitational neutrino
mass model in [Dvali, Funcke, Phys. Rev. D 93, 113002 (2016)]. In the
transition, global skyrmions, monopoles, strings, and domain walls form due to
the spontaneous breaking of the neutrino flavor symmetry. These defects are
unique in their softness and origin; as they appear at a very low energy scale,
they only require Standard Model particle content, and they differ
fundamentally depending on the Majorana or Dirac nature of the neutrinos. One
of the observational signatures is the time dependence and space dependence of
the neutrino mass matrix, which could be observable in future neutrino
experiments. Already existing data rule out parts of the parameter space in the
Majorana case. The detection of this effect could shed light onto the open
question of the Dirac versus Majorana neutrino nature.
- Short-baseline oscillation scenarios at JUNO and TAO
2112.00379 [abs] [pdf]
[abstract]
by V. S. Basto-Gonzalez, [and 4 more]D. V. Forero, C. Giunti, A. A. Quiroga, and C. A. Ternes [hide authors].
We study the sensitivity of JUNO and TAO to the oscillations induced by two
well-motivated scenarios beyond the standard model: Large Extra Dimensions
(LED) and light sterile neutrinos in the context of 3+1 neutrino mixing. We
find that JUNO+TAO can set competitive bounds on the parameter space of each
scenario. In particular, we find that JUNO+TAO can be competitive with MINOS,
DUNE or KATRIN in the context of LED. If LED are present in nature, we show
that the parameters could be measured with a similar precision as the standard
oscillation parameters. We also show that JUNO+TAO can test nearly all of the
parameter space preferred by Gallium experiments in the context of 3+1 mixing.
Finally, we discuss the possibility to distinguish the two scenarios from each
other.
November 2021
- Leptogenesis and eV scale sterile neutrino
2111.14719 [abs] [pdf]
[abstract]
by Srubabati Goswami, [and 3 more]Vishnudath K. N., Ananya Mukherjee, and Nimmala Narendra [hide authors].
We consider the minimal extended seesaw model which can accommodate an eV
scale sterile neutrino. The scenario also includes three heavy right handed
neutrinos in addition to the light sterile neutrino. In this model, the
active-sterile mixing act as non-unitary parameters. If the values of these
mixing angles are of $\mathcal{O}(0.1)$, the model introduces deviation of the
PMNS matrix from unitarity to this order. We find that the oscillation data
from various experiments imposes an upper bound on the lightest heavy neutrino
mass scale as $\sim 10^{11}$ GeV in the context of this model. We study {\it
vanilla} leptogenesis in this scheme, where the decay of the heavy right handed
neutrinos in the early universe can give rise to the observed baryon asymmetry.
Here, even though the eV scale sterile neutrino does not participate directly
in leptogenesis, its effect is manifested through the non-unitary effects. We
find that the parameter space that can give rise to successful leptogenesis is
constrained by the bounds on the active-sterile mixing as obtained from the
global analysis.
- The UHECR dipole and quadrupole in the latest data from the original
Auger and TA surface detectors
2111.14593 [abs] [pdf]
[abstract]
by Peter Tinyakov, [and 15 more]Luis Anchordoqui, Teresa Bister, Jonathan Biteau, Lorenzo Caccianiga, Rogério de Almeida, Olivier Deligny, Armando di Matteo, Ugo Giaccari, Diego Harari, Jihyun Kim, Mikhail Kuznetsov, Ioana Mariş, Grigory Rubtsov, Sergey Troitsky, and Federico Urban [hide authors].
The sources of ultra-high-energy cosmic rays are still unknown, but assuming
standard physics, they are expected to lie within a few hundred megaparsecs
from us. Indeed, over cosmological distances cosmic rays lose energy to
interactions with background photons, at a rate depending on their mass number
and energy and properties of photonuclear interactions and photon backgrounds.
The universe is not homogeneous at such scales, hence the distribution of the
arrival directions of cosmic rays is expected to reflect the inhomogeneities in
the distribution of galaxies; the shorter the energy loss lengths, the stronger
the expected anisotropies. Galactic and intergalactic magnetic fields can blur
and distort the picture, but the magnitudes of the largest-scale anisotropies,
namely the dipole and quadrupole moments, are the most robust to their effects.
Measuring them with no bias regardless of any higher-order multipoles is not
possible except with full-sky coverage. In this work, we achieve this in three
energy ranges (approximately 8--16 EeV, 16--32 EeV, and 32--$\infty$ EeV) by
combining surface-detector data collected at the Pierre Auger Observatory until
2020 and at the Telescope Array (TA) until 2019, before the completion of the
upgrades of the arrays with new scintillator detectors. We find that the
full-sky coverage achieved by combining Auger and TA data reduces the
uncertainties on the north-south components of the dipole and quadrupole in
half compared to Auger-only results.
- Non-minimal Lorentz invariance violation in light of muon anomalous
magnetic moment and long-baseline neutrino oscillation data
2111.14336 [abs] [pdf]
[abstract]
by Hai-Xing Lin, [and 3 more]Pedro Pasquini, Jian Tang, and Sampsa Vihonen [hide authors].
In light of the increasing hints of new physics at the muon $g-2$ and
neutrino oscillation experiments, we consider the recently observed tension in
the long-baseline neutrino oscillation experiments as a potential indication of
Lorentz invariance violation. For this purpose, the latest data from T2K and
NO$\nu$A is analysed in presence of non-minimal Lorentz invariance violation.
Indeed, we find that isotropic violation in dimensions $D =$ 4, 5 and 6 can
alleviate the tension in neutrino oscillation data by 0.4$-$2.4$\sigma$ CL
significance, with the isotropic coefficient $\gamma^{(5)}_{\tau \tau} =$
3.58$\times$10$^{-32}$GeV$^{-1}$ yielding the best fit. At the same time, the
anomalous muon $g-2$ result can be reproduced with an additional non-isotropic
violation of $d^{zt} =$ -1.7$\times$10$^{-25}$. The analysis highlights the
possibility of simultaneous relaxation of experimental tensions with Lorentz
invariance violation of mixed nature.
- Neutrino propagation when mass eigenstates and decay eigenstates
mismatch
2111.13128 [abs] [pdf]
[abstract]
by Dibya S. Chattopadhyay, [and 4 more]Kaustav Chakraborty, Amol Dighe, Srubabati Goswami, and S. M. Lakshmi [hide authors].
We point out that the Hermitian and anti-Hermitian components of the
effective Hamiltonian for decaying neutrinos cannot be simultaneously
diagonalized by unitary transformations for all matter densities. We develop a
formalism for the two-flavor neutrino propagation through matter of uniform
density, for neutrino decay to invisible states. Employing a resummation of the
Zassenhaus expansion, we obtain compact analytic expressions for neutrino
survival and conversion probabilities, to first and second order in the
"mismatch parameter" $\bar{\gamma}$.
- T-violating effect in $ν_τ (\barν_τ)-$nucleon
quasielastic scattering
2111.13021 [abs] [pdf]
[abstract]
by A. Fatima, M. Sajjad Athar, and S. K. Singh.
The production cross sections and polarization observables of the $\tau$
leptons produced in the $|\Delta S| = 0$ and $1$ induced
$\nu_{\tau}(\bar{\nu}_{\tau})-N$ quasielastic scattering have been studied. The
effect of T violation, in the case of $\Delta S=0$ and 1 processes, and the
SU(3) symmetry breaking effects, in the case of $\Delta S=1$ processes, on the
total scattering cross sections as well polarization observables are explored.
Experimentally, it would be possible to observe these effects in the
forthcoming (anti)neutrino experiments like DUNE, SHiP and DsTau.
- Exploring the effects of Scalar Non Standard Interactions on the CP
violation sensitivity at DUNE
2111.12943 [abs] [pdf]
[abstract]
by Abinash Medhi, Debajyoti Dutta, and Moon Moon Devi.
The Neutrino oscillations have provided an excellent opportunity to study
new-physics beyond the Standard Model, popularly known as BSM. The unknown
couplings involving neutrinos, termed non-standard interactions (NSI), may
appear as `new-physics' in different neutrino experiments. The neutrino NSI
offers significant effects on neutrino oscillations and CP-sensitivity, which
may be probed in various neutrino experiments. The idea of neutrinos coupling
with a scalar has evolved recently and looks promising. The effects of scalar
NSI may appear as a perturbation to the neutrino mass matrix in the neutrino
Hamiltonian. It modifies the neutrino mass matrix and may provide a direct
possibility of probing neutrino mass models. As the scalar NSI affects the
neutrino mass matrix in the Hamiltonian, its effect is energy independent.
Moreover, the matter effects due to scalar NSI scales linearly with the matter
density.
In this work, we have performed a model-independent study of the effects of
scalar NSI at long baseline neutrino experiments, taking DUNE as a case study.
We have performed such a thorough study for DUNE for the first time. Various
neutrino parameters may get affected due to the inclusion of scalar NSI as it
modifies the effective mass matrix of neutrinos. We have explored the impact of
scalar NSI in neutrino oscillations and its impact on the measurements of
various mixing parameters. We have probed the effects of scalar NSI on
different oscillation channels relevant to the experiment. We have also
explored the impact of various possible elements in the scalar NSI term on the
CP-violation sensitivity at DUNE.
- What can CMB observations tell us about the neutrino distribution
function?
2111.12726 [abs] [pdf]
[abstract]
by James Alvey, Miguel Escudero, and Nashwan Sabti.
Cosmic Microwave Background (CMB) observations have been used extensively to
constrain key properties of neutrinos, such as their mass. However, these
inferences are typically dependent on assumptions about the cosmological model,
and in particular upon the distribution function of neutrinos in the early
Universe. In this paper, we aim to assess the full extent to which CMB
experiments are sensitive to the shape of the neutrino distribution. We
demonstrate that Planck and CMB-S4-like experiments have no prospects for
detecting particular features in the distribution function. Consequently, we
take a general approach and marginalise completely over the form of the
neutrino distribution to derive constraints on the relativistic and
non-relativistic neutrino energy densities, characterised by $N_\mathrm{eff} =
3.0 \pm 0.4$ and $\rho_{\nu,0}^{\rm NR} < 14 \, \mathrm{eV}\,\mathrm{cm}^{-3}$
at 95% CL, respectively. The fact that these are the only neutrino properties
that CMB data can constrain has important implications for neutrino mass limits
from cosmology. Specifically, in contrast to the $\Lambda$CDM case where CMB
and BAO data tightly constrain the sum of neutrinos masses to be $\sum m_\nu <
0.12 \, \mathrm{eV}$, we explicitly show that neutrino masses as large as $\sum
m_\nu \sim 3 \, \mathrm{eV}$ are perfectly consistent with this data.
Importantly, for this to be the case, the neutrino number density should be
suitably small such that the bound on $\rho_{\nu,0}^\mathrm{NR} = \sum m_\nu
n_{\nu,0}$ is still satisfied. We conclude by giving an outlook on the
opportunities that may arise from other complementary experimental probes, such
as galaxy surveys, neutrino mass experiments and facilities designed to
directly detect the cosmic neutrino background.
- Statistical significance of the sterile-neutrino hypothesis in the
context of reactor and gallium data
2111.12530 [abs] [pdf]
[abstract]
by Jeffrey M. Berryman, [and 4 more]Pilar Coloma, Patrick Huber, Thomas Schwetz, and Albert Zhou [hide authors].
We evaluate the statistical significance of the 3+1 sterile-neutrino
hypothesis using $\nu_e$ and $\bar\nu_e$ disappearance data from reactor, solar
and gallium radioactive source experiments. Concerning the latter, we
investigate the implications of the recent BEST results. For reactor data we
focus on relative measurements independent of flux predictions. For the problem
at hand, the usual $\chi^2$-approximation to hypothesis testing based on Wilks'
theorem has been shown in the literature to be inaccurate. We therefore present
results based on Monte Carlo simulations, and find that this typically reduces
the significance by roughly $1\,\sigma$ with respect to the na\"ive
expectation. We find no significant indication in favor of sterile-neutrino
oscillations from reactor data. On the other hand, gallium data (dominated by
the BEST result) show more than $5\,\sigma$ of evidence supporting the
sterile-neutrino hypothesis, favoring oscillation parameters in agreement with
constraints from reactor data. This explanation is, however, in significant
tension ($\sim 3\,\sigma$) with solar neutrino experiments. In order to assess
the robustness of the signal for gallium experiments we present a discussion of
the impact of cross-section uncertainties on the results.
- A close look on 2-3 mixing angle with DUNE in light of current neutrino
oscillation data
2111.11748 [abs] [pdf]
[abstract]
by Sanjib Kumar Agarwalla, [and 3 more]Ritam Kundu, Suprabh Prakash, and Masoom Singh [hide authors].
Recent global fit analyses of oscillation data show a preference for normal
mass ordering (NMO) at 2.5$\sigma$ and provide 1.6$\sigma$ indications for
lower $\theta_{23}$ octant and leptonic CP violation. A high-precision
measurement of $\theta_{23}$ is pivotal to convert these hints into
discoveries. In this work, we study in detail the capabilities of DUNE to
establish the deviation from maximal $\theta_{23}$ and to resolve its octant at
high confidence levels. We exhibit the possible correlations and degeneracies
among $\sin^2\theta_{23}$, $\Delta m^2_{31}$, and $\delta_{CP}$ in
disappearance and appearance oscillation channels at the probability and event
levels. Introducing for the first time, a bi-events plot in the plane of total
$\nu$ and $\bar\nu$ disappearance events, we discuss the impact of
$\sin^2\theta_{23}$ - $\Delta m^2_{31}$ degeneracy in establishing non-maximal
$\theta_{23}$ and show how this degeneracy can be resolved by exploiting the
spectral shape information in $\nu$ and $\bar\nu$ disappearance events. A
3$\sigma$ (5$\sigma$) determination of non-maximal $\theta_{23}$ is possible in
DUNE in total 7 years if $\sin^2\theta_{23} \lesssim 0.465~(0.450)$ or
$\sin^2\theta_{23} \gtrsim 0.554~(0.572)$ for any value of $\delta_{CP}$ and
NMO. We study the individual contributions from appearance and disappearance
channels, impact of systematic uncertainties and marginalization over
oscillation parameters, importance of spectral analysis and data from both
$\nu$ and $\bar\nu$ runs, while analyzing DUNE's sensitivity to establish
non-maximal $\theta_{23}$. DUNE can resolve the octant of $\theta_{23}$ at
4.2$\sigma$ (5$\sigma$) using 7 (10) years of run assuming $\sin^2\theta_{23}$
= 0.455, $\delta_{CP}$ = $223^\circ$, and NMO. DUNE can improve the current
relative 1$\sigma$ precision on $\sin^2\theta_{23}$ ($\Delta m^2_{31}$) by a
factor of 4.4 (2.8) using 7 years of run.
- Improved Characterization of the Astrophysical Muon-Neutrino Flux with
9.5 Years of IceCube Data
2111.10299 [abs] [pdf]
[abstract]
by R. Abbasi, [and 379 more]M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, J. M. Alameddine, C. Alispach, A. A. Alves Jr., N. M. Amin, K. Andeen, T. Anderson, G. Anton, C. Argüelles, Y. Ashida, S. Axani, X. Bai, A. Balagopal V., A. Barbano, S. W. Barwick, B. Bastian, V. Basu, S. Baur, R. Bay, J. J. Beatty, K. -H. Becker, J. Becker Tjus, C. Bellenghi, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, G. Binder, D. Bindig, E. Blaufuss, S. Blot, M. Boddenberg, F. Bontempo, J. Borowka, S. Böser, O. Botner, J. Böttcher, E. Bourbeau, F. Bradascio, J. Braun, B. Brinson, S. Bron, J. Brostean-Kaiser, S. Browne, A. Burgman, R. T. Burley, R. S. Busse, M. A. Campana, E. G. Carnie-Bronca, C. Chen, Z. Chen, D. Chirkin, K. Choi, B. A. Clark, K. Clark, L. Classen, A. Coleman, G. H. Collin, J. M. Conrad, P. Coppin, P. Correa, D. F. Cowen, R. Cross, C. Dappen, P. Dave, C. De Clercq, J. J. DeLaunay, D. Delgado López, H. Dembinski, K. Deoskar, A. Desai, P. Desiati, K. D. de Vries, G. de Wasseige, M. de With, T. DeYoung, A. Diaz, J. C. Díaz-Vélez, M. Dittmer, H. Dujmovic, M. Dunkman, M. A. DuVernois, E. Dvorak, T. Ehrhardt, P. Eller, R. Engel, H. Erpenbeck, J. Evans, P. A. Evenson, K. L. Fan, A. R. Fazely, A. Fedynitch, N. Feigl, S. Fiedlschuster, A. T. Fienberg, K. Filimonov, C. Finley, L. Fischer, D. Fox, A. Franckowiak, E. Friedman, A. Fritz, P. Fürst, T. K. Gaisser, J. Gallagher, E. Ganster, A. Garcia, S. Garrappa, L. Gerhardt, A. Ghadimi, C. Glaser, T. Glauch, T. Glüsenkamp, J. G. Gonzalez, S. Goswami, D. Grant, T. Grégoire, S. Griswold, C. Günther, P. Gutjahr, C. Haack, A. Hallgren, R. Halliday, L. Halve, F. Halzen, M. Ha Minh, K. Hanson, J. Hardin, A. A. Harnisch, A. Haungs, D. Hebecker, K. Helbing, F. Henningsen, E. C. Hettinger, S. Hickford, J. Hignight, C. Hill, G. C. Hill, K. D. Hoffman, R. Hoffmann, B. Hokanson-Fasig, K. Hoshina, F. Huang, M. Huber, T. Huber, K. Hultqvist, M. Hünnefeld, R. Hussain, K. Hymon, S. In, N. Iovine, A. Ishihara, M. Jansson, G. S. Japaridze, M. Jeong, M. Jin, B. J. P. Jones, D. Kang, W. Kang, X. Kang, A. Kappes, D. Kappesser, L. Kardum, T. Karg, M. Karl, A. Karle, U. Katz, M. Kauer, M. Kellermann, J. L. Kelley, A. Kheirandish, K. Kin, T. Kintscher, J. Kiryluk, S. R. Klein, R. Koirala, H. Kolanoski, T. Kontrimas, L. Köpke, C. Kopper, S. Kopper, D. J. Koskinen, P. Koundal, M. Kovacevich, M. Kowalski, T. Kozynets, E. Kun, N. Kurahashi, N. Lad, C. Lagunas Gualda, J. L. Lanfranchi, M. J. Larson, F. Lauber, J. P. Lazar, J. W. Lee, K. Leonard, A. Leszczyńska, Y. Li, M. Lincetto, Q. R. Liu, M. Liubarska, E. Lohfink, C. J. Lozano Mariscal, L. Lu, F. Lucarelli, A. Ludwig, W. Luszczak, Y. Lyu, W. Y. Ma, J. Madsen, K. B. M. Mahn, Y. Makino, S. Mancina, I. C. Mariş, I. Martinez-Soler, R. Maruyama, K. Mase, T. McElroy, F. McNally, J. V. Mead, K. Meagher, S. Mechbal, A. Medina, M. Meier, S. Meighen-Berger, J. Micallef, D. Mockler, T. Montaruli, R. W. Moore, R. Morse, M. Moulai, R. Naab, R. Nagai, U. Naumann, J. Necker, L. V. Nguyên, H. Niederhausen, M. U. Nisa, S. C. Nowicki, A. Obertacke Pollmann, M. Oehler, B. Oeyen, A. Olivas, E. O'Sullivan, H. Pandya, D. V. Pankova, N. Park, G. K. Parker, E. N. Paudel, L. Paul, C. Pérez de los Heros, L. Peters, J. Peterson, S. Philippen, S. Pieper, M. Pittermann, A. Pizzuto, M. Plum, Y. Popovych, A. Porcelli, M. Prado Rodriguez, P. B. Price, B. Pries, G. T. Przybylski, C. Raab, A. Raissi, M. Rameez, K. Rawlins, I. C. Rea, A. Rehman, P. Reichherzer, R. Reimann, G. Renzi, E. Resconi, S. Reusch, W. Rhode, M. Richman, B. Riedel, E. J. Roberts, S. Robertson, G. Roellinghoff, M. Rongen, C. Rott, T. Ruhe, D. Ryckbosch, D. Rysewyk Cantu, I. Safa, J. Saffer, S. E. Sanchez Herrera, A. Sandrock, J. Sandroos, M. Santander, S. Sarkar, S. Sarkar, K. Satalecka, M. Schaufel, H. Schieler, S. Schindler, T. Schmidt, A. Schneider, J. Schneider, F. G. Schröder, L. Schumacher, G. Schwefer, S. Sclafani, D. Seckel, S. Seunarine, A. Sharma, S. Shefali, M. Silva, B. Skrzypek, B. Smithers, R. Snihur, J. Soedingrekso, D. Soldin, C. Spannfellner, G. M. Spiczak, C. Spiering, J. Stachurska, M. Stamatikos, T. Stanev, R. Stein, J. Stettner, A. Steuer, T. Stezelberger, T. Stürwald, T. Stuttard, G. W. Sullivan, I. Taboada, S. Ter-Antonyan, S. Tilav, F. Tischbein, K. Tollefson, C. Tönnis, S. Toscano, D. Tosi, A. Trettin, M. Tselengidou, C. F. Tung, A. Turcati, R. Turcotte, C. F. Turley, J. P. Twagirayezu, B. Ty, M. A. Unland Elorrieta, N. Valtonen-Mattila, J. Vandenbroucke, N. van Eijndhoven, D. Vannerom, J. van Santen, S. Verpoest, C. Walck, T. B. Watson, C. Weaver, P. Weigel, A. Weindl, M. J. Weiss, J. Weldert, C. Wendt, J. Werthebach, M. Weyrauch, N. Whitehorn, C. H. Wiebusch, D. R. Williams, M. Wolf, K. Woschnagg, G. Wrede, J. Wulff, X. W. Xu, J. P. Yanez, S. Yoshida, S. Yu, T. Yuan, Z. Zhang, and P. Zhelnin [hide authors].
We present a measurement of the high-energy astrophysical muon-neutrino flux
with the IceCube Neutrino Observatory. The measurement uses a high-purity
selection of ~650k neutrino-induced muon tracks from the Northern celestial
hemisphere, corresponding to 9.5 years of experimental data. With respect to
previous publications, the measurement is improved by the increased size of the
event sample and the extended model testing beyond simple power-law hypotheses.
An updated treatment of systematic uncertainties and atmospheric background
fluxes has been implemented based on recent models. The best-fit single
power-law parameterization for the astrophysical energy spectrum results in a
normalization of $\phi_{\mathrm{@100TeV}}^{\nu_\mu+\bar{\nu}_\mu} =
1.44_{-0.26}^{+0.25} \times
10^{-18}\,\mathrm{GeV}^{-1}\mathrm{cm}^{-2}\mathrm{s}^{-1}\mathrm{sr}^{-1}$ and
a spectral index $\gamma_{\mathrm{SPL}} = 2.37_{-0.09}^{+0.09}$, constrained in
the energy range from $15\,\mathrm{TeV}$ to $5\,\mathrm{PeV}$. The model tests
include a single power law with a spectral cutoff at high energies, a
log-parabola model, several source-class specific flux predictions from the
literature and a model-independent spectral unfolding. The data is well
consistent with a single power law hypothesis, however, spectra with softening
above one PeV are statistically more favorable at a two sigma level.
- Neutrino meets ultralight dark matter: $\boldsymbol{0νββ}$
decay and cosmology
2111.08732 [abs] [pdf]
[abstract]
by Guo-yuan Huang and Newton Nath.
We explore the neutrinoless double beta ($0\nu \beta\beta$) decay induced by
an ultralight dark matter field coupled to neutrinos. The effect on
$0\nu\beta\beta$ decay is significant if the coupling violates the lepton
number, for which the $\Delta L=2$ transition is directly driven by the dark
matter field without further suppression of small neutrino masses. As the
ultralight dark matter can be well described by a classical field, the effect
features a periodic modulation pattern in decay events. However, we find that
in the early Universe such coupling will be very likely to alter the standard
cosmological results. In particular, the requirement of neutrino free-streaming
before the matter-radiation equality severely constrains the parameter space,
such that the future $0\nu \beta\beta$ decay experiments can hardly see any
signal even with a meV sensitivity to the effective neutrino mass.
- Nonunitarity of the lepton mixing matrix at the European Spallation
Source
2111.08673 [abs] [pdf]
[abstract]
by Sabya Sachi Chatterjee, [and 3 more]O. G. Miranda, M. Tórtola, and J. W. F. Valle [hide authors].
If neutrinos get mass through the exchange of lepton mediators, as in seesaw
schemes, the neutrino appearance probabilities in oscillation experiments are
modified due to effective nonunitarity of the lepton mixing matrix. This also
leads to new CP phases and an ambiguity in underpinning the ''conventional''
phase of the three-neutrino paradigm. We study the CP sensitivities of various
setups based at the European spallation source neutrino super-beam (ESSnuSB)
experiment in the presence of nonunitarity. We also examine its potential in
constraining the associated new physics parameters. Moreover, we show how the
combination of DUNE and ESSnuSB can help further improve the sensitivities on
the nonunitarity parameters.
- Non-standard Neutrino and $Z'$ Interactions at the FASER$ν$ and the
LHC
2111.08375 [abs] [pdf]
[abstract]
by Kingman Cheung, C. J. Ouseph, and TseChun Wang.
We study the impact of non-standard neutrino interactions in the context of a
new gauge boson $Z'$ in neutral-current deep-inelastic scattering performed in
ForwArd Search ExpeRiment-$\nu$ (FASER$\nu$) and in monojet production at the
Large Hadron Collider (LHC). We simulate the neutral-current deep-inelastic
neutrino-nucleon scattering $\nu N \rightarrow \nu N$ at FASER$\nu$ in the
presence of an additional $Z'$ boson, and estimate the anticipated
sensitivities to the gauge coupling in a wide range of $Z'$ mass. At the LHC,
we study the effect of $Z'$ on monojet production, which can be enhanced in
regions with large missing transverse momenta. We then use the recent results
from ATLAS with an integrated luminosity of 139 fb$^{-1}$ to improve the limits
on the gauge coupling of $Z'$. We interpret such limits on $Z'$ gauge couplings
as bounds on effective non-standard neutrino interactions. We show that the
FASER$\rm \nu$ and the LHC results cover the medium and high energy scales,
respectively, and complement one another.
- Status and Perspectives of Neutrino Physics
2111.07586 [abs] [pdf]
[abstract]
by M. Sajjad Athar, [and 18 more]Steven W. Barwick, Thomas Brunner, Jun Cao, Mikhail Danilov, Kunio Inoue, Takaaki Kajita, Marek Kowalski, Manfred Lindner, Kenneth R. Long, Nathalie Palanque-Delabrouille, Werner Rodejohann, Heidi Schellman, Kate Scholberg, Seon-Hee Seo, Nigel J. T. Smith, Walter Winter, Geralyn P. Zeller, and Renata Zukanovich Funchal [hide authors].
This review demonstrates the unique role of the neutrino by discussing in
detail the physics of and with neutrinos. We deal with neutrino sources,
neutrino oscillations, absolute masses, interactions, the possible existence of
sterile neutrinos, and theoretical implications. In addition, synergies of
neutrino physics with other research fields are found, and requirements to
continue successful neutrino physics in the future, in terms of technological
developments and adequate infrastructures, are stressed.
- Probing Neutrino-Portal Dark Matter at the Forward Physics Facility
2111.05868 [abs] [pdf]
[abstract]
by Kevin J. Kelly, [and 3 more]Felix Kling, Douglas Tuckler, and Yue Zhang [hide authors].
The Forward Physics Facility (FPF), planned to operate near the ATLAS
interaction point at the LHC, offers exciting new terrain to explore neutrino
properties at TeV energy scales. It will reach an unprecedented regime for
terrestrial neutrino experiments and provide the opportunity to reveal new
physics of neutrinos at higher energy scales. We demonstrate that future
detectors at the FPF have the potential to discover new mediators that couple
predominantly to neutrinos, with masses between 0.3 and 20 GeV and small
couplings not yet probed by existing searches. Such a neutrinophilic mediator
is well motivated for addressing the origin of several neutrino-portal dark
matter candidates, including thermal freeze-out and sterile-neutrino dark
matter scenarios. Experimentally, the corresponding signatures include neutrino
charged-current scattering events associated with large missing transverse
momentum, and excessive apparent tau-neutrino events. We discuss the FPF
detector capabilities needed for this search, most importantly the hadronic
energy resolution.
- Sterile Neutrino Searches with MicroBooNE: Electron Neutrino
Disappearance
2111.05793 [abs] [pdf]
[abstract]
by Peter B. Denton.
A sterile neutrino is a well motivated minimal new physics model that leaves
an imprint in neutrino oscillations. Over the last two decades, a number of
hints pointing to a sterile neutrino have emerged, many of which are pointing
near $m_4\sim1$ eV. Here we show how MicroBooNE data can be used to search for
electron neutrino disappearance using each of their four analysis channels. We
find a hint for oscillations with the highest single channel significance of
$2.4\sigma$ (using the Feldman-Cousins approach) coming from the Wire-Cell
analysis and a simplified treatment of the experimental systematics. The
preferred parameters are $\sin^2(2\theta_{14})=0.35^{+0.19}_{-0.16}$ and
$\Delta m^2_{41}=1.25^{+0.74}_{-0.39}$ eV$^2$. This region of parameter space
is in good agreement with existing hints from source experiments, is at a
similar frequency but higher mixing than indicated by reactor anti-neutrinos,
and is at the edge of the region allowed by solar neutrino data. Existing
unanalyzed data from MicroBooNE could increase the sensitivity to the
$>3\sigma$ level.
- Scalable Qubit Representations of Neutrino Mixing Matrices
2111.05401 [abs] [pdf]
[abstract]
by M. J. Molewski and B. J. P. Jones.
Oscillating neutrino beams exhibit quantum coherence over distances of
thousands of kilometers. Their unambiguously quantum nature suggests an
appealing test system for direct quantum simulation. Such techniques may enable
presently analytically intractable calculations involving multi-neutrino
entanglements, such as collective neutrino oscillations in supernovae, but only
once oscillation phenomenology is properly re-expressed in the language of
quantum circuits. Here we resolve outstanding conceptual issues regarding
encoding of arbitrarily mixed neutrino flavor states in the Hilbert space of an
n-qubit quantum computer. We introduce algorithms to encode mixing and
oscillation of any number of flavor-mixed neutrinos, both with and without
CP-violation, with an efficient number of prescriptive input parameters in
terms of sub-rotations of the PMNS matrix in standard form. Examples encoded
for an IBM-Q quantum computer are shown to converge to analytic predictions
both with and without CP-violation.
- Galactic rotation curves versus ultralight dark matter: A systematic
comparison with SPARC data
2111.03070 [abs] [pdf]
[abstract]
by Nitsan Bar, Kfir Blum, and Chen Sun.
We look for and place observational constraints on the imprint of ultralight
dark matter (ULDM) soliton cores in rotation-dominated galaxies. Extending
previous analyses, we find a conservative constraint which disfavors the
soliton-host halo relation found in some numerical simulations over a broad
range in the ULDM particle mass $m$. Combining the observational constraints
with theoretical arguments for the efficiency of soliton formation via
gravitational dynamical relaxation, and assuming that the soliton-halo relation
is correct, our results disfavor ULDM from comprising 100\% of the total
cosmological dark matter in the range $10^{-24}~{\rm eV}\lesssim
m\lesssim10^{-20}~{\rm eV}$. The constraints probe the ULDM fraction down to
$f\lesssim0.3$ of the total dark matter.
- Non-standard interactions from the future neutrino solar sector
2111.03031 [abs] [pdf]
[abstract]
by P. Martínez-Miravé, S. Molina Sedgwick, and M. Tórtola.
The next-generation neutrino experiment JUNO will determine the solar
oscillation parameters - $\sin^2 \theta_{12}$ and $\Delta m^2_{21}$ - with
great accuracy, in addition to measuring $\sin^2\theta_{13}$, $\Delta
m^2_{31}$, and the mass ordering. In parallel, the continued study of solar
neutrinos at Hyper-Kamiokande will provide complementary measurements in the
solar sector. In this paper, we address the expected sensitivity to
non-universal and flavour-changing non-standard interactions (NSI) with
$d$-type quarks from the combination of these two future neutrino experiments.
We also show the robustness of their measurements of the solar parameters
$\sin^2 \theta_{12}$ and $\Delta m^2_{21}$ in the presence of NSI. We study the
impact of the exact experimental configuration of the Hyper-Kamiokande
detector, and conclude it is of little relevance in this scenario. Finally, we
find that the LMA-D solution is expected to be present if no additional input
from non-oscillation experiments is considered.
- $pp$ Solar Neutrinos at DARWIN
2111.02421 [abs] [pdf]
[abstract]
by André de Gouvêa, [and 3 more]Emma McGinness, Ivan Martinez-Soler, and Yuber F. Perez-Gonzalez [hide authors].
The DARWIN collaboration recently argued that DARWIN (DARk matter WImp search
with liquid xenoN) can collect, via neutrino--electron scattering, a large,
useful sample of solar $pp$-neutrinos, and measure their survival probability
with sub-percent precision. We explore the physics potential of such a sample
in more detail. We estimate that, with 300 ton-years of data, DARWIN can also
measure, with the help of current solar neutrino data, the value of
$\sin^2\theta_{13}$, with the potential to exclude $\sin^2\theta_{13}=0$ close
to the three-sigma level. We explore in some detail how well DARWIN can
constrain the existence of a new neutrino mass-eigenstate $\nu_4$ that is
quasi-mass-degenerate with $\nu_1$ and find that DARWIN's sensitivity
supersedes that of all current and near-future searches for new, very light
neutrinos. In particular, DARWIN can test the hypothesis that $\nu_1$ is a
pseudo-Dirac fermion as long as the induced mass-squared difference is larger
than $10^{-13}$ eV$^2$, one order of magnitude more sensitive than existing
constraints. Throughout, we allowed for the hypotheses that DARWIN is filled
with natural xenon or $^{136}$Xe-depleted xenon.
October 2021
- Anisotropies of ultrahigh-energy cosmic rays in a scenario with nearby
sources
2111.00560 [abs] [pdf]
[abstract]
by Silvia Mollerach and Esteban Roulet.
The images of ultrahigh-energy cosmic ray sources get distorted, in an energy
dependent way, by the effects of Galactic and extragalactic magnetic fields.
These deflections can also affect the observed cosmic ray spectrum, specially
when the sources are transient. We study scenarios in which one or a few nearby
extragalactic sources, such as CenA or M81/M82, provide the dominant
contribution to the cosmic ray flux above the ankle of the spectrum. We discuss
the effects of the angular dispersion induced by the turbulent extragalactic
magnetic fields, and the coherent deflections caused by the regular Galactic
magnetic field, with the associated multiple imaging of the sources. We
consider the possible contribution from those sources to the dipolar
distribution discovered by the Pierre Auger Observatory above 8 EeV, as well as
to the hot spots hinted in the observations by the Pierre Auger and Telescope
Array observatories at higher energies, taking into account the mixed nature of
the cosmic ray composition.
- Model-Independent Constraints on Non-Unitary Neutrino Mixing from
High-Precision Long-Baseline Experiments
2111.00329 [abs] [pdf]
[abstract]
by Sanjib Kumar Agarwalla, [and 3 more]Sudipta Das, Alessio Giarnetti, and Davide Meloni [hide authors].
Our knowledge on the active 3$\nu$ mixing angles ($\theta_{12}$,
$\theta_{13}$, and $\theta_{23}$) and the CP phase $\delta_{\mathrm{CP}}$ is
becoming accurate day-by-day enabling us to test the unitarity of the leptonic
mixing matrix with utmost precision. Future high-precision long-baseline
experiments are going to play an important role in this direction. In this
work, we study the impact of possible non-unitary neutrino mixing (NUNM) in the
context of next-generation long-baseline experiments DUNE and T2HKK/JD+KD
having one detector in Japan (T2HK/JD) and a second detector in Korea (KD). We
estimate the sensitivities of these setups to place direct, model-independent,
and competitive constraints on various NUNM parameters. We demonstrate the
possible correlations between the NUNM parameters, $\theta_{23}$, and
$\delta_{\mathrm{CP}}$. Our numerical results obtained using only far detector
data and supported by simple approximate analytical expressions of the
oscillation probabilities in matter, reveal that JD+KD has better sensitivities
for $|\alpha_{21}|$ and $\alpha_{22}$ as compared to DUNE, due to its larger
statistics in the appearance channel and less systematic uncertainties in the
disappearance channel, respectively. For $|\alpha_{31}|$, $|\alpha_{32}|$, and
$\alpha_{33}$, DUNE gives better constraints as compared to JD+KD, due to its
larger matter effect and wider neutrino energy spectrum. For $\alpha_{11}$,
both DUNE and JD+KD give similar bounds. We also show how much the bounds on
the NUNM parameters can be improved by combining the prospective data from DUNE
and JD+KD setups. We find that due to zero-distance effects, the near detectors
alone can also constrain $\alpha_{11}$, $|\alpha_{21}|$, and $\alpha_{22}$ in
both these setups. Finally, we observe that the $\nu_\tau$ appearance sample in
DUNE can improve the constraints on $|\alpha_{32}|$ and $\alpha_{33}$.
- Time variation of the atmospheric neutrino flux at dark matter detectors
2110.14723 [abs] [pdf]
[abstract]
by Yi Zhuang, Louis E. Strigari, and Rafael F. Lang.
The cosmic ray flux at the lowest energies, $\lesssim 10$ GeV, is modulated
by the solar cycle, inducing a time variation that is expected to carry over
into the atmospheric neutrino flux at these energies. Here we estimate this
time variation of the atmospheric neutrino flux at five prospective underground
locations for multi-tonne scale dark matter detectors (CJPL, Kamioka, LNGS,
SNOlab and SURF). We find that between solar minimum and solar maximum, the
normalization of the flux changes by $\sim 30\%$ at a high-latitude location
such as SURF, while it changes by a smaller amount, $\lesssim 10\%$, at LNGS. A
dark matter detector that runs for a period extending through solar cycles will
be most effective at identifying this time variation. This opens the
possibility to distinguish such neutrino-induced nuclear recoils from dark
matter-induced nuclear recoils, thus allowing for the possibility of using
timing information to break through the "neutrino floor."
- TauRunner: A Public Python Program to Propagate Neutral and Charged
Leptons
2110.14662 [abs] [pdf]
[abstract]
by Ibrahim Safa, [and 5 more]Jeffrey Lazar, Alex Pizzuto, Oswaldo Vasquez, Carlos A. Argüelles, and Justin Vandenbroucke [hide authors].
In the past decade IceCube's observations have revealed a flux of
astrophysical neutrinos extending to $10^{7}~\rm{GeV}$. The forthcoming
generation of neutrino observatories promises to grant further insight into the
high-energy neutrino sky, with sensitivity reaching energies up to
$10^{12}~\rm{GeV}$. At such high energies, a new set of effects becomes
relevant, which was not accounted for in the last generation of neutrino
propagation software. Thus, it is important to develop new simulations which
efficiently and accurately model lepton behavior at this scale. We present
TauRunner a PYTHON-based package that propagates neutral and charged leptons.
TauRunner supports propagation between $10~\rm{GeV}$ and $10^{12}~\rm{GeV}$.
The package accounts for all relevant secondary neutrinos produced in
charged-current tau neutrino interactions. Additionally, tau energy losses of
taus produced in neutrino interactions is taken into account, and treated
stochastically. Finally, TauRunner is broadly adaptable to divers experimental
setups, allowing for user-specified trajectories and propagation media,
neutrino cross sections, and initial spectra.
- A full parametrization of the $9\times 9$ active-sterile flavor mixing
matrix in the inverse or linear seesaw scenario of massive neutrinos
2110.12705 [abs] [pdf]
[abstract]
by He-chong Han and Zhi-zhong Xing.
The inverse and linear seesaw scenarios are two typical extensions of the
canonical seesaw mechanism, which contain much more sterile degrees of freedom
but can naturally explain the smallness of three active neutrino masses at a
sufficiently low energy scale (e.g., the TeV scale). To fully describe the
mixing among three active neutrinos, three sterile neutrinos and three extra
gauge-singlet neutral fermions in either of these two seesaw paradigms, we
present the {\it first} full parametrization of the $9\times 9$ flavor mixing
matrix in terms of 36 rotation angles and 36 CP-violating phases. The exact
inverse and linear seesaw formulas are derived, respectively; and possible
deviations of the $3\times 3$ active neutrino mixing matrix from its unitary
limit are discussed by calculating the effective Jarlskog invariants and
unitarity nonagons.
- Measurement of the Coherent Elastic Neutrino-Nucleus Scattering Cross
Section on CsI by COHERENT
2110.07730 [abs] [pdf]
[abstract]
by D. Akimov, [and 75 more]P. An, C. Awe, P. S. Barbeau, B. Becker, V. Belov, I. Bernardi, M. A. Blackston, C. Bock, A. Bolozdynya, J. Browning, B. Cabrera-Palmer, D. Chernyak, E. Conley, J. Daughhetee, J. Detwiler, K. Ding, M. R. Durand, Y. Efremenko, S. R. Elliott, L. Fabris, M. Febbraro, A. Gallo Rosso, A. Galindo-Uribarri, M. P. Green, M. R. Heath, S. Hedges, D. Hoang, M. Hughes, T. Johnson, A. Khromov, A. Konovalov, E. Kozlova, A. Kumpan, L. Li, J. M. Link, J. Liu, K. Mann, D. M. Markoff, J. Mastroberti, P. E. Mueller, J. Newby, D. S. Parno, S. I. Penttila, D. Pershey, R. Rapp, H. Ray, J. Raybern, O. Razuvaeva, D. Reyna, G. C. Rich, J. Ross, D. Rudik, J. Runge, D. J. Salvat, A. M. Salyapongse, K. Scholberg, A. Shakirov, G. Simakov, G. Sinev, W. M. Snow, V. Sosnovstsev, B. Suh, R. Tayloe, K. Tellez-Giron-Flores, I. Tolstukhin, E. Ujah, J. Vanderwerp, R. L. Varner, C. J. Virtue, G. Visser, T. Wongjirad, Y. -R. Yen, J. Yoo, C. -H. Yu, and J. Zettlemoyer [hide authors].
We measured the cross section of coherent elastic neutrino-nucleus scattering
(\cevns{}) using a CsI[Na] scintillating crystal in a high flux of neutrinos
produced at the Spallation Neutron Source (SNS) at Oak Ridge National
Laboratory. New data collected before detector decommissioning has more than
doubled the dataset since the first observation of \cevns{}, achieved with this
detector. Systematic uncertainties have also been reduced with an updated
quenching model, allowing for improved precision. With these analysis
improvements, the COHERENT collaboration determined the cross section to be
$(165^{+30}_{-25})\times10^{-40}$~cm$^2$, consistent with the standard model,
giving the most precise measurement of \cevns{} yet. The timing structure of
the neutrino beam has been exploited to compare the \cevns{} cross section from
scattering of different neutrino flavors. This result places leading
constraints on neutrino non-standard interactions while testing lepton flavor
universality and measures the weak mixing angle as
$\sin^2\theta_{W}=0.220^{+0.028}_{-0.026}$ at $Q^2\approx(50\text{ MeV})^2$
- Ultra-high-energy neutrino scattering in an anomalous U(1) effective
field theory
2110.07517 [abs] [pdf]
[abstract]
by Chuan-Hung Chen, Cheng-Wei Chiang, and Chun-Wei Su.
A unique characteristic of exponentially growing scattering amplitude arises
in an anomalous Abelian effective field theory when an extremely light Dirac
neutrino mass is introduced to break the symmetry. We show that the low energy
effective Lagrangian can be made explicitly gauge invariant with the help of a
nonlinear representation of the Goldstone or Stueckelberg field. We study the
peculiar feature of exponential growth in the ultra-high-energy
neutrino-nucleon inelastic scattering. It is found that the inelastic
scattering cross section is highly sensitive to the ratio of gauge coupling to
the gauge boson mass, $g_X/m_X$. When the IceCube measurement of
ultra-high-energy neutrinos, which is consistent with the standard model
prediction up to $E_\nu \sim 6$ PeV, is taken into account, the inferred
constraint on $g_X/m_X$ is more severe than that obtained from the events of
mono-lepton$+$missing transverse energy at the LHC. A muon collider with a
collision energy of $10$ TeV can be a good environment other than hadron
colliders to probe the novel effect.
- Reactor antineutrino anomaly in light of recent flux model refinements
2110.06820 [abs] [pdf]
[abstract]
by C. Giunti, [and 3 more]Y. F. Li, C. A. Ternes, and Z. Xin [hide authors].
We study the status of the reactor antineutrino anomaly in light of recent
reactor flux models obtained with the conversion and summation methods. We
present a new improved calculation of the IBD yields of the standard
Huber-Mueller (HM) model and those of the new models. We show that the reactor
rates and the fuel evolution data are consistent with the predictions of the
Kurchatov Institute (KI) conversion model and with those of the Estienne-Fallot
(EF) summation model, leading to a plausible robust demise of the reactor
antineutrino anomaly. We show that the results of several goodness of fit tests
favor the KI and EF models over other models that we considered. We also
discuss the implications of the new reactor flux models for short-baseline
neutrino oscillations due to active-sterile oscillations. We show that reactor
data give upper bounds on active-sterile neutrino mixing that are not very
different for the reactor flux models under consideration and are in tension
with the large mixing required by the Gallium anomaly that has been refreshed
by the recent results of the BEST experiment.
- Effect of non-unitary mixing on the mass hierarchy and CP violation
determination at the Protvino to Orca experiment
2110.02917 [abs] [pdf]
[abstract]
by Daljeet Kaur, Nafis Rezwan Khan Chowdhury, and Ushak Rahaman.
In this paper, we have estimated the neutrino mass ordering and the CP
violation sensitivity of the proposed Protvino to Orca (P2O) experiment after 6
years of data-taking. Both unitary and non-unitary $3\times 3$ neutrino mass
mixing have been considered in the simulations. A forecast analysis deriving
possible future constraints on non-unitary parameters at P2O have been
performed.
- Novel constraints on neutrino physics beyond the standard model from the
CONUS experiment
2110.02174 [abs] [pdf]
[abstract]
by CONUS Collaboration, [and 12 more]H. Bonet, A. Bonhomme, C. Buck, K. Fülber, J. Hakenmüller, G. Heusser, T. Hugle, M. Lindner, W. Maneschg, T. Rink, H. Strecker, and R. Wink [hide authors].
The measurements of coherent elastic neutrino-nucleus scattering (CE$\nu$NS)
experiments have opened up the possibility to constrain neutrino physics beyond
the standard model of elementary particle physics. Furthermore, by considering
neutrino-electron scattering in the keV-energy region, it is possible to set
additional limits on new physics processes. Here, we present constraints that
are derived from CONUS germanium data on beyond the standard model (BSM)
processes like tensor and vector non-standard interactions (NSIs) in the
neutrino-quark sector, as well as light vector and scalar mediators. Thanks to
the realized low background levels in the CONUS experiment at ionization
energies below 1 keV, we are able to set the world's best limits on tensor NSIs
from CE$\nu$NS and constrain the scale of corresponding new physics to lie
above 360 GeV. For vector NSIs, the derived limits strongly depend on the
assumed ionization quenching factor within the detector material, since small
quenching factors largely suppress potential signals for both, the expected
standard model CE$\nu$NS process and the vector NSIs. Furthermore, competitive
limits on scalar and vector mediators are obtained from the CE$\nu$NS channel
at reactor-site which allow to probe coupling constants as low as
$5\cdot10^{-5}$ of low mediator masses, assuming the currently favored
quenching factor regime. The consideration of neutrino-electron scatterings
allows to set even stronger constraints for mediator masses below $\sim1$ MeV
and $\sim 10$ MeV for scalar and vector mediators, respectively.
- Neutrino Oscillations through the Earth's Core
2110.01148 [abs] [pdf]
[abstract]
by Peter B. Denton and Rebekah Pestes.
Neutrinos have two properties that make them fairly unique from other known
particles: extremely low cross sections and flavor changing oscillations. With
a good knowledge of the oscillation parameters soon in hand, it will become
possible to detect low-energy atmospheric neutrinos sensitive to the forward
elastic scattering off electrons in the Earth's core providing a measurement of
the core properties and the matter effect itself. As the dynamics of the
Earth's core are complicated and in a difficult to probe environment,
additional information from upcoming neutrino experiments will provide feedback
into our knowledge of geophysics as well as useful information about exoplanet
formation and various new physics scenarios including dark matter. In addition,
we can probe the existence of the matter effect in the Earth and constrain the
non-standard neutrino interaction parameter $\epsilon_{ee}^\oplus$. We show how
DUNE's sensitivity to low-energy atmospheric neutrino oscillations can provide
a novel constraint on the density and radius of the Earth's core at the 9\%
level and the Earth's matter effect at the 5\% level. Finally, we illuminate
the physics behind low-energy atmospheric neutrino resonances in the Earth.
- Search for Neutrino-Induced Neutral Current $Δ$ Radiative Decay in
MicroBooNE and a First Test of the MiniBooNE Low Energy Excess Under a
Single-Photon Hypothesis
2110.00409 [abs] [pdf]
[abstract]
by MicroBooNE collaboration, [and 187 more]P. Abratenko, R. An, J. Anthony, L. Arellano, J. Asaadi, A. Ashkenazi, S. Balasubramanian, B. Baller, C. Barnes, G. Barr, V. Basque, L. Bathe-Peters, O. Benevides Rodrigues, S. Berkman, A. Bhanderi, A. Bhat, M. Bishai, A. Blake, T. Bolton, J. Y. Book, L. Camilleri, D. Caratelli, I. Caro Terrazas, R. Castillo Fernandez, F. Cavanna, G. Cerati, Y. Chen, D. Cianci, J. M. Conrad, M. Convery, L. Cooper-Troendle, J. I. Crespo-Anadon, M. Del Tutto, S. R. Dennis, P. Detje, A. Devitt, R. Diurba, R. Dorrill, K. Duffy, S. Dytman, B. Eberly, A. Ereditato, J. J. Evans, R. Fine, G. A. Fiorentini Aguirre, R. S. Fitzpatrick, B. T. Fleming, N. Foppiani, D. Franco, A. P. Furmanski, D. Garcia-Gamez, S. Gardiner, G. Ge, S. Gollapinni, O. Goodwin, E. Gramellini, P. Green, H. Greenlee, W. Gu, R. Guenette, P. Guzowski, L. Hagaman, O. Hen, C. Hilgenberg, G. A. Horton-Smith, A. Hourlier, R. Itay, C. James, X. Ji, L. Jiang, J. H. Jo, R. A. Johnson, Y. J. Jwa, D. Kalra, N. Kamp, N. Kaneshige, G. Karagiorgi, W. Ketchum, M. Kirby, T. Kobilarcik, I. Kreslo, R. LaZur, I. Lepetic, K. Li, Y. Li, K. Lin, B. R. Littlejohn, W. C. Louis, X. Luo, K. Manivannan, C. Mariani, D. Marsden, J. Marshall, D. A. Martinez Caicedo, K. Mason, A. Mastbaum, N. McConkey, V. Meddage, T. Mettler, K. Miller, J. Mills, K. Mistry, T. Mohayai, A. Mogan, J. Moon, M. Mooney, A. F. Moor, C. D. Moore, L. Mora Lepin, J. Mousseau, M. Murphy, D. Naples, A. Navrer-Agasson, M. Nebot-Guinot, R. K. Neely, D. A. Newmark, J. Nowak, M. Nunes, O. Palamara, V. Paolone, A. Papadopoulou, V. Papavassiliou, S. F. Pate, N. Patel, A. Paudel, Z. Pavlovic, E. Piasetzky, I. Ponce-Pinto, S. Prince, X. Qian, J. L. Raaf, V. Radeka, A. Rafique, M. Reggiani-Guzzo, L. Ren, L. C. J. Rice, L. Rochester, J. Rodriguez Rondon, M. Rosenberg, M. Ross-Lonergan, G. Scanavini, D. W. Schmitz, A. Schukraft, W. Seligman, M. H. Shaevitz, R. Sharankova, J. Shi, J. Sinclair, A. Smith, E. L. Snider, M. Soderberg, S. Soldner-Rembold, P. Spentzouris, J. Spitz, M. Stancari, J. St. John, T. Strauss, K. Sutton, S. Sword-Fehlberg, A. M. Szelc, W. Tang, K. Terao, C. Thorpe, D. Totani, M. Toups, Y. -T. Tsai, M. A. Uchida, T. Usher, W. Van De Pontseele, B. Viren, M. Weber, H. Wei, Z. Williams, S. Wolbers, T. Wongjirad, M. Wospakrik, K. Wresilo, N. Wright, W. Wu, E. Yandel, T. Yang, G. Yarbrough, L. E. Yates, H. W. Yu, G. P. Zeller, J. Zennamo, and C. Zhang [hide authors].
We report results from a search for neutrino-induced neutral current (NC)
resonant $\Delta$(1232) baryon production followed by $\Delta$ radiative decay,
with a $\langle0.8\rangle$~GeV neutrino beam. Data corresponding to
MicroBooNE's first three years of operations (6.80$\times$10$^{20}$ protons on
target) are used to select single-photon events with one or zero protons and
without charged leptons in the final state ($1\gamma1p$ and $1\gamma0p$,
respectively). The background is constrained via an in-situ high-purity
measurement of NC $\pi^0$ events, made possible via dedicated $2\gamma1p$ and
$2\gamma0p$ selections. A total of 16 and 153 events are observed for the
$1\gamma1p$ and $1\gamma0p$ selections, respectively, compared to a constrained
background prediction of $20.5 \pm 3.65 \text{(sys.)} $ and $145.1 \pm 13.8
\text{(sys.)} $ events. The data lead to a bound on an anomalous enhancement of
the normalization of NC $\Delta$ radiative decay of less than $2.3$ times the
predicted nominal rate for this process at the 90% confidence level (CL). The
measurement disfavors a candidate photon interpretation of the MiniBooNE
low-energy excess as a factor of $3.18$ times the nominal NC $\Delta$ radiative
decay rate at the 94.8% CL, in favor of the nominal prediction, and represents
a greater than $50$-fold improvement over the world's best limit on
single-photon production in NC interactions in the sub-GeV neutrino energy
range
September 2021
- DUNE atmospheric neutrinos: Earth Tomography
2110.00003 [abs] [pdf]
[abstract]
by Kevin J. Kelly, [and 3 more]Pedro A. N. Machado, Ivan Martinez-Soler, and Yuber F. Perez-Gonzalez [hide authors].
In this paper we show that the DUNE experiment can measure the Earth's
density profile by analyzing atmospheric neutrino oscillations. The crucial
feature that enables such measurement is the detailed event reconstruction
capability of liquid argon time projection chambers. This allows for studying
the sub-GeV atmospheric neutrino component, which bears a rich oscillation
phenomenology, strongly dependent on the matter potential sourced by the Earth.
We provide a pedagogical discussion of the MSW and parametric resonances and
their role in measuring the core and mantle densities. By performing a detailed
simulation, accounting for particle reconstruction at DUNE, nuclear physics
effects relevant to neutrino-argon interactions and several uncertainties on
the atmospheric neutrino flux, we manage to obtain a robust estimate of DUNE's
sensitivity to the Earth matter profile. We find that DUNE can measure the
total mass of the Earth at 8.4% precision with an exposure of 400~kton-year. By
accounting for previous measurements of the total mass and moment of inertia of
the Earth, the core, lower mantle and upper mantle densities can be determined
with 8.8%, 13% and 22% precision, respectively, for the same exposure. Finally,
DUNE could take atmospheric neutrino data while the beam is being commissioned
and far detector modules are up and running. For a low exposure run of
60~kton-year, which would correspond to two far detectors running for three
years, we have found that the core density could be measured by DUNE at
$\sim30\%$ precision.
- Testing sterile neutrino mixing with present and future solar neutrino
data
2109.14898 [abs] [pdf]
[abstract]
by Kim Goldhagen, [and 3 more]Michele Maltoni, Shayne Reichard, and Thomas Schwetz [hide authors].
We investigate the sensitivity of solar neutrino data to mixing of sterile
neutrinos with masses $\gtrsim$ eV. For current data, we perform a
Feldman-Cousins analysis to derive a robust limit on the sterile neutrino
mixing. The solar neutrino limit excludes significant regions of the parameter
space relevant to hints from reactor and radioactive gallium source
experiments. We then study the sensitivity of upcoming solar neutrino data,
most notably elastic neutrino-electron scattering in the DARWIN and DUNE
experiments as well as coherent neutrino-nucleus scattering in DARWIN. These
high precision measurements will increase the sensitivity to sterile neutrino
mixing by about a factor of 4.5 compared to present limits. As a by-product, we
introduce a simplified solar neutrino analysis using only four data points: the
low- and high-energy $\nu_e$ survival and transition probabilities. We show
that this simplified analysis is in excellent agreement with a full solar
neutrino analysis; it is very easy to handle numerically and can be applied to
any new physics model in which the energy dependence of the $\nu_e$ transition
probabilities is not significantly modified.
- Tau Neutrino Identification in Atmospheric Neutrino Oscillations Without
Particle Identification or Unitarity
2109.14576 [abs] [pdf]
[abstract]
by Peter B. Denton.
The largest tau neutrino dataset to date is IceCube's atmospheric tau
neutrino appearance dataset containing $>1,000$ tau neutrino and antineutrino
events as determined by a fit to a standard three-flavor oscillation framework.
On an event-by-event basis, however, it is impossible to know that any given
event is a tau neutrino as they are identical to either an electron neutrino
charged-current event or a neutral-current interaction of any active flavor.
Nonetheless, we conclusively show that, using only the cascade sample even
without knowledge of the oscillation parameters and without assuming that the
lepton mixing matrix is unitary, tau neutrino identification is still possible
and there is no viable scenario in which all of the tau neutrino candidates are
actually electron neutrinos. This is primarily due to the matter effect and the
tau lepton production threshold, as well as the fact that tau neutrinos are
systematically reconstructed at a lower energy than electron neutrinos due to
one or more outgoing neutrinos. This conclusively shows that it is possible for
an atmospheric neutrino oscillation experiment to confirm that $U_{\tau1}$,
$U_{\tau2}$, and $U_{\tau3}$ are not all zero even with limited particle
identification.
- New oscillation and scattering constraints on the tau row matrix
elements without assuming unitarity
2109.14575 [abs] [pdf]
[abstract]
by Peter B. Denton and Julia Gehrlein.
The tau neutrino is the least well measured particle in the Standard Model.
Most notably, the tau neutrino row of the lepton mixing matrix is quite poorly
constrained when unitarity is not assumed. In this paper, we identify data sets
involving tau neutrinos that improve our understanding of the tau neutrino part
of the mixing matrix, in particular $\nu_\tau$ appearance in atmospheric
neutrinos. We present new results on the elements of the tau row leveraging
existing constraints on the electron and muon rows for the cases of unitarity
violation, with and without kinematically accessible steriles. We also show the
expected sensitivity due to upcoming experiments and demonstrate that the tau
neutrino row precision may be comparable to the muon neutrino row in a careful
combined fit.
- Lorentz symmetry and high-energy neutrino astronomy
2109.13973 [abs] [pdf]
[abstract]
by Carlos A. Argüelles and Teppei Katori.
The search of violation of Lorentz symmetry, or Lorentz violation (LV), is an
active research field. The effects of LV are expected to be very small and
special systems are often used to search it. High-energy astrophysical
neutrinos offer a unique system to search signatures of LV due to the three
factors: high neutrino energy, long propagation distance, and the presence of
quantum mechanical interference. In this brief review, we introduce tests of LV
and summarize existing searches of LV using atmospheric and astrophysical
neutrinos.
- Non-unitary Leptonic Flavor Mixing and CP Violation in
Neutrino-antineutrino Oscillations
2109.13622 [abs] [pdf]
[abstract]
by Yilin Wang and Shun Zhou.
If massive neutrinos are Majorana particles, then the lepton number should be
violated in nature and neutrino-antineutrino oscillations $\nu^{}_\alpha
\leftrightarrow \overline{\nu}^{}_\beta$ (for $\alpha, \beta = e, \mu, \tau$)
will definitely take place. In the present paper, we study the properties of CP
violation in neutrino-antineutrino oscillations with the non-unitary leptonic
flavor mixing matrix, which is actually a natural prediction in the canonical
seesaw model due to the mixing between light and heavy Majorana neutrinos. The
oscillation probabilities $P(\nu^{}_\alpha \to \overline{\nu}^{}_\beta)$ and
$P(\overline{\nu}^{}_\alpha \to \nu^{}_\beta)$ are derived, and the CP
asymmetries ${\cal A}^{}_{\alpha \beta} \equiv [P(\nu^{}_\alpha \to
\overline{\nu}^{}_\beta) - P(\overline{\nu}^{}_\alpha \to
\nu^{}_\beta)]/[P(\nu^{}_\alpha \to \overline{\nu}^{}_\beta) +
P(\overline{\nu}^{}_\alpha \to \nu^{}_\beta)]$ are also calculated. Taking into
account current experimental bounds on the leptonic unitarity violation, we
show that the CP asymmetries induced by the non-unitary mixing parameters can
significantly deviate from those in the limit of a unitary leptonic flavor
mixing.
- Updating $ν_{3}$ lifetime from solar antineutrino spectra
2109.13272 [abs] [pdf]
[abstract]
by R. Picoreti, [and 3 more]D. Pramanik, P. C. de Holanda, and O. L. G. Peres [hide authors].
We study the production of antineutrinos from the solar neutrinos due the
Majorana neutrino decays of neutrino to antineutrino. Using the antineutrino
spectra from KamLAND and Borexino, we present newest limits on the lifetime of
$\nu_{3}$ in this scenario. We consider $\nu_{3} \rightarrow \bar{\nu}_{1} + X$
and $\nu_{3} \rightarrow \bar{\nu}_{2} + X$ channels assuming scalar or
pseudo-scalar interactions. For hierarchical mass-splittings, the limits
obtained by us are $\tau_{3}/m_{3}~\geq 7\times 10^{-5} s/eV$ and
$\tau_{3}/m_{3}~\geq 1\times 10^{-5} s/eV$ for the two channels at $90\%$ C.L.
We found that the newest bound is five orders of magnitude better than the
atmospheric and long-baseline bounds.
- Diffuse Supernova Neutrino Background Search at Super-Kamiokande
2109.11174 [abs] [pdf]
[abstract]
by Super-Kamiokande Collaboration, [and 221 more]:, K. Abe, C. Bronner, Y. Hayato, K. Hiraide, M. Ikeda, S. Imaizumi, J. Kameda, Y. Kanemura, Y. Kataoka, S. Miki, M. Miura, S. Moriyama, Y. Nagao, M. Nakahata, S. Nakayama, T. Okada, K. Okamoto, A. Orii, G. Pronost, H. Sekiya, M. Shiozawa, Y. Sonoda, Y. Suzuki, A. Takeda, Y. Takemoto, A. Takenaka, H. Tanaka, S. Watanabe, T. Yano, S. Han, T. Kajita, K. Okumura, T. Tashiro, J. Xia, G. D. Megias, D. Bravo-Bergu, L. Labarga, Ll. Marti, B. Zaldivar, B. W. Pointon, F. d. M. Blaszczyk, E. Kearns, J. L. Raaf, J. L. Stone, L. Wan, T. Wester, J. Bian, N. J. Griskevich, W. R. Kropp, S. Locke, S. Mine, M. B. Smy, H. W. Sobel, V. Takhistov, J. Hill, J. Y. Kim, I. T. Lim, R. G. Park, B. Bodur, K. Scholberg, C. W. Walter, S. Cao, L. Bernard, A. Coffani, O. Drapier, S. El Hedri, A. Giampaolo, M. Gonin, Th. A. Mueller, P. Paganini, B. Quilain, T. Ishizuka, T. Nakamura, J. S. Jang, J. G. Learned, L. H. V. Anthony, D. Martin, M. Scott, A. A. Sztuc, Y. Uchida, V. Berardi, M. G. Catanesi, E. Radicioni, N. F. Calabria, L. N. Machado, G. De Rosa, G. Collazuol, F. Iacob, M. Lamoureux, M. Mattiazzi, N. Ospina, L. Ludovici, Y. Maekawa, Y. Nishimura, M. Friend, T. Hasegawa, T. Ishida, T. Kobayashi, M. Jakkapu, T. Matsubara, T. Nakadaira, K. Nakamura, Y. Oyama, K. Sakashita, T. Sekiguchi, T. Tsukamoto, Y. Kotsar, Y. Nakano, H. Ozaki, T. Shiozawa, A. T. Suzuki, Y. Takeuchi, S. Yamamoto, A. Ali, Y. Ashida, J. Feng, S. Hirota, T. Kikawa, M. Mori, T. Nakaya, R. A. Wendell, K. Yasutome, P. Fernandez, N. McCauley, P. Mehta, K. M. Tsui, Y. Fukuda, Y. Itow, H. Menjo, T. Niwa, K. Sato, M. Tsukada, J. Lagoda, S. M. Lakshmi, P. Mijakowski, J. Zalipska, J. Jiang, C. K. Jung, C. Vilela, M. J. Wilking, C. Yanagisawa, K. Hagiwara, M. Harada, T. Horai, H. Ishino, S. Ito, H. Kitagawa, Y. Koshio, W. Ma, N. Piplani, S. Sakai, G. Barr, D. Barrow, L. Cook, A. Goldsack, S. Samani, D. Wark, F. Nova, T. Boschi, F. Di Lodovico, J. Gao, J. Migenda, M. Taani, S. Zsoldos, J. Y. Yang, S. J. Jenkins, M. Malek, J. M. McElwee, O. Stone, M. D. Thiesse, L. F. Thompson, H. Okazawa, S. B. Kim, J. W. Seo, I. Yu, K. Nishijima, M. Koshiba, K. Iwamoto, K. Nakagiri, Y. Nakajima, N. Ogawa, M. Yokoyama, K. Martens, M. R. Vagins, M. Kuze, S. Izumiyama, T. Yoshida, M. Inomoto, M. Ishitsuka, H. Ito, T. Kinoshita, R. Matsumoto, K. Ohta, M. Shinoki, T. Suganuma, A. K. Ichikawa, K. Nakamura, J. F. Martin, H. A. Tanaka, T. Towstego, R. Akutsu, V. Gousy-Leblanc, M. Hartz, A. Konaka, P. de Perio, N. W. Prouse, S. Chen, B. D. Xu, Y. Zhang, M. Posiadala-Zezula, D. Hadley, M. O'Flaherty, B. Richards, B. Jamieson, J. Walker, A. Minamino, K. Okamoto, G. Pintaudi, S. Sano, and R. Sasaki [hide authors].
A new search for the diffuse supernova neutrino background (DSNB) flux has
been conducted at Super-Kamiokande (SK), with a $22.5\times2970$-kton$\cdot$day
exposure from its fourth operational phase IV. The new analysis improves on the
existing background reduction techniques and systematic uncertainties and takes
advantage of an improved neutron tagging algorithm to lower the energy
threshold compared to the previous phases of SK. This allows for setting the
world's most stringent upper limit on the extraterrestrial $\bar{\nu}_e$ flux,
for neutrino energies below 31.3 MeV. The SK-IV results are combined with the
ones from the first three phases of SK to perform a joint analysis using
$22.5\times5823$ kton$\cdot$days of data. This analysis has the world's best
sensitivity to the DSNB $\bar{\nu}_e$ flux, comparable to the predictions from
various models. For neutrino energies larger than 17.3 MeV, the new combined
$90\%$ C.L. upper limits on the DSNB $\bar{\nu}_e$ flux lie around $2.7$
cm$^{-2}$$\cdot$$\text{sec}^{-1}$, strongly disfavoring the most optimistic
predictions. Finally, potentialities of the gadolinium phase of SK and the
future Hyper-Kamiokande experiment are discussed.
- The Forward Physics Facility: Sites, Experiments, and Physics Potential
2109.10905 [abs] [pdf]
[abstract]
by Luis A. Anchordoqui, [and 80 more]Akitaka Ariga, Tomoko Ariga, Weidong Bai, Kincso Balazs, Brian Batell, Jamie Boyd, Joseph Bramante, Mario Campanelli, Adrian Carmona, Francesco G. Celiberto, Grigorios Chachamis, Matthew Citron, Giovanni De Lellis, Albert De Roeck, Hans Dembinski, Peter B. Denton, Antonia Di Crecsenzo, Milind V. Diwan, Liam Dougherty, Herbi K. Dreiner, Yong Du, Rikard Enberg, Yasaman Farzan, Jonathan L. Feng, Max Fieg, Patrick Foldenauer, Saeid Foroughi-Abari, Alexander Friedland, Michael Fucilla, Jonathan Gall, Maria Vittoria Garzelli, Francesco Giuli, Victor P. Goncalves, Marco Guzzi, Francis Halzen, Juan Carlos Helo, Christopher S. Hill, Ahmed Ismail, Ameen Ismail, Richard Jacobsson, Sudip Jana, Yu Seon Jeong, Krzysztof Jodlowski, Kevin J. Kelly, Felix Kling, Fnu Karan Kumar, Zhen Liu, Rafal Maciula, Roshan Mammen Abraham, Julien Manshanden, Josh McFayden, Mohammed M. A. Mohammed, Pavel M. Nadolsky, Nobuchika Okada, John Osborne, Hidetoshi Otono, Vishvas Pandey, Alessandro Papa, Digesh Raut, Mary Hall Reno, Filippo Resnati, Adam Ritz, Juan Rojo, Ina Sarcevic, Christiane Scherb, Holger Schulz, Pedro Schwaller, Dipan Sengupta, Torbjörn Sjöstrand, Tyler B. Smith, Dennis Soldin, Anna Stasto, Antoni Szczurek, Zahra Tabrizi, Sebastian Trojanowski, Yu-Dai Tsai, Douglas Tuckler, Martin W. Winkler, Keping Xie, and Yue Zhang [hide authors].
The Forward Physics Facility (FPF) is a proposal to create a cavern with the
space and infrastructure to support a suite of far-forward experiments at the
Large Hadron Collider during the High Luminosity era. Located along the beam
collision axis and shielded from the interaction point by at least 100 m of
concrete and rock, the FPF will house experiments that will detect particles
outside the acceptance of the existing large LHC experiments and will observe
rare and exotic processes in an extremely low-background environment. In this
work, we summarize the current status of plans for the FPF, including recent
progress in civil engineering in identifying promising sites for the FPF and
the experiments currently envisioned to realize the FPF's physics potential. We
then review the many Standard Model and new physics topics that will be
advanced by the FPF, including searches for long-lived particles, probes of
dark matter and dark sectors, high-statistics studies of TeV neutrinos of all
three flavors, aspects of perturbative and non-perturbative QCD, and
high-energy astroparticle physics.
- Potential for a precision measurement of solar $pp$ neutrinos in the
Serappis Experiment
2109.10782 [abs] [pdf]
[abstract]
by Lukas Bieger, [and 58 more]Thilo Birkenfeld, David Blum, Wilfried Depnering, Timo Enqvist, Heike Enzmann, Feng Gao, Christoph Genster, Alexandre Göttel, Christian Grewing, Maxim Gromov, Paul Hackspacher, Caren Hagner, Tobias Heinz, Philipp Kampmann, Michael Karagounis, Andre Kruth, Pasi Kuusiniemi, Tobias Lachenmaier, Daniel Liebau, Runxuan Liu, Kai Loo, Livia Ludhova, David Meyhöfer, Axel Müller, Pavithra Muralidharan, Lothar Oberauer, Rainer Othegraven, Nina Parkalian, Yatian Pei, Oliver Pilarczyk, Henning Rebber, Markus Robens, Christian Roth, Julia Sawatzki, Konstantin Schweizer, Giulio Settanta, Maciej Slupecki, Oleg Smirnov, Achim Stahl, Hans Steiger, Jochen Steinmann, Tobias Sterr, Matthias Raphael Stock, Jian Tang, Eric Theisen, Alexander Tietzsch, Wladyslaw Trzaska, Johannes van den Boom, Stefan van Waasen, Cornelius Vollbrecht, Christopher Wiebusch, Bjoern Wonsak, Michael Wurm, Christian Wysotzki, Yu Xu, Ugur Yegin, Andre Zambanini, and Jan Züfle [hide authors].
The Serappis (SEarch for RAre PP-neutrinos In Scintillator) project aims at a
precision measurement of the flux of solar $pp$ neutrinos on the few-percent
level. Such a measurement will be a relevant contribution to the study of solar
neutrino oscillation parameters and a sensitive test of the solar luminosity
constraint. The concept of Serappis relies on a small organic liquid
scintillator detector ($\sim$20 m$^3$) with excellent energy resolution
($\sim$2.5 % at 1 MeV), low internal background and sufficient shielding from
surrounding radioactivity. This can be achieved by a minor upgrade of the
OSIRIS facility at the site of the JUNO neutrino experiment in southern China.
To go substantially beyond current accuracy levels for the $pp$ flux, an
organic scintillator with ultra-low $^{14}$C levels (below $10^{-18}$) is
required. The existing OSIRIS detector and JUNO infrastructure will be
instrumental in identifying suitable scintillator materials, offering a unique
chance for a low-budget high-precision measurement of a fundamental property of
our Sun that will be otherwise hard to access.
- Monte Carlo simulations of neutrino and charged lepton propagation in
the Earth with nuPyProp
2109.08198 [abs] [pdf]
[abstract]
by Sameer Patel, [and 18 more]Mary Hall Reno, Yosui Akaike, Luis Anchordoqui, Douglas Bergman, Isaac Buckland, Austin Cummings, Johannes Eser, Claire Guépin, John F. Krizmanic, Simon Mackovjak, Angela Olinto, Thomas Paul, Alex Reustle, Andrew Romero-Wolf, Fred Sarazin, Tonia Venters, Lawrence Wiencke, and Stephanie Wissel [hide authors].
An accurate modeling of neutrino flux attenuation and the distribution of
leptons they produce in transit through the Earth is an essential component to
determine neutrino flux sensitivities of underground, sub-orbital and
space-based detectors. Through neutrino oscillations over cosmic distances,
astrophysical neutrino sources are expected to produce nearly equal fluxes of
electron, muon and tau neutrinos. Of particular interest are tau neutrinos that
interact in the Earth at modest slant depths to produce $\tau$-leptons. Some
$\tau$-leptons emerge from the Earth and decay in the atmosphere to produce
extensive air showers. Future balloon-borne and satellite-based optical
Cherenkov neutrino telescopes will be sensitive to upward air showers from tau
neutrino induced $\tau$-lepton decays. We present nuPyProp, a python code that
is part of the nuSpaceSim package. nuPyProp generates look-up tables for exit
probabilities and energy distributions for $\nu_\tau\to \tau$ and $\nu_\mu\to
\mu$ propagation in the Earth. This flexible code runs with either stochastic
or continuous electromagnetic energy losses for the lepton transit through the
Earth. Current neutrino cross section models and energy loss models are
included along with templates for user input of other models. Results from
nuPyProp are compared with other recent simulation packages for neutrino and
charged lepton propagation. Sources of modeling uncertainties are described and
quantified.
- SNEWPY: A Data Pipeline from Supernova Simulations to Neutrino Signals
2109.08188 [abs] [pdf]
[abstract]
by Amanda L. Baxter, [and 19 more]Segev BenZvi, Joahan Castaneda Jaimes, Alexis Coleiro, Marta Colomer Molla, Damien Dornic, Tomer Goldhagen, Anne M. Graf, Spencer Griswold, Alec Habig, Remington Hill, Shunsaku Horiuchi James P. Kneller Rafael F. Lang, Massimiliano Lincetto, Jost Migenda, Ko Nakamura, Evan O'Connor, Andrew Renshaw, Kate Scholberg, Navya Uberoi, and Arkin Worlikar [hide authors].
Current neutrino detectors will observe hundreds to thousands of neutrinos
from a Galactic supernovae, and future detectors will increase this yield by an
order of magnitude or more. With such a data set comes the potential for a huge
increase in our understanding of the explosions of massive stars, nuclear
physics under extreme conditions, and the properties of the neutrino. However,
there is currently a large gap between supernova simulations and the
corresponding signals in neutrino detectors, which will make any comparison
between theory and observation very difficult. SNEWPY is an open-source
software package which bridges this gap. The SNEWPY code can interface with
supernova simulation data to generate from the model either a time series of
neutrino spectral fluences at Earth, or the total time-integrated spectral
fluence. Data from several hundred simulations of core-collapse, thermonuclear,
and pair-instability supernovae is included in the package. This output may
then be used by an event generator such as sntools or an event rate calculator
such as SNOwGLoBES. Additional routines in the SNEWPY package automate the
processing of the generated data through the SNOwGLoBES software and collate
its output into the observable channels of each detector. In this paper we
describe the contents of the package, the physics behind SNEWPY, the
organization of the code, and provide examples of how to make use of its
capabilities.
- An Altarelli Cocktail for the MiniBooNE Anomaly?
2109.08157 [abs] [pdf]
[abstract]
by Vedran Brdar and Joachim Kopp.
We critically examine a number of theoretical uncertainties affecting the
MiniBooNE short-baseline neutrino oscillation experiment in an attempt to
better understand the observed excess of electron-like events. We re-examine
the impact of fake charged current quasi-elastic (CCQE) events, the background
due to neutral current $\pi^0$ production, and the single-photon background.
For all processes, we compare the predictions of different event generators
(GENIE, GiBUU, NUANCE, and NuWro) and, for GENIE, of different tunes. Where
MiniBooNE uses data-driven background predictions, we discuss the uncertainties
affecting the relation between the signal sample and the control sample. In the
case of the single-photon background, we emphasize the uncertainties in the
radiative branching ratios of heavy hadronic resonances. We find that not even
a combination of uncertainties in different channels adding up unfavorably (an
"Altarelli cocktail") appears to be sufficient to resolve the MiniBooNE
anomaly. We finally investigate how modified background predictions affect the
fit of a $3+1$ sterile neutrino scenario. We carefully account for full
four-flavor oscillations not only in the signal, but also in the background and
control samples. We emphasize that because of the strong correlation between
MiniBooNE's $\nu_e$ and $\nu_\mu$ samples, a sterile neutrino mixing only with
$\nu_\mu$ is sufficient to explain the anomaly, even though the well-known
tension with external constraints on $\nu_\mu$ disappearance persists.
- Measuring tau neutrino appearance probability via unitarity
2109.06933 [abs] [pdf]
[abstract]
by Ivan Martinez-Soler and Hisakazu Minakata.
We propose a {\em unitarity method} for determining $\tau$ neutrino
appearance probability $P(\nu_{\mu} \rightarrow \nu_{\tau})$ in long-baseline
(LBL) accelerator experiments and atmospheric neutrino observations. When
simultaneous in situ measurements of $P(\nu_{\mu} \rightarrow \nu_{\mu})$ and
$P(\nu_{\mu} \rightarrow \nu_{e})$ proceed, as is typical in the LBL
experiments, one can use unitarity to "measure" $P(\nu_{\mu} \rightarrow
\nu_{\tau})$. A theorists' toy analysis for the model-independent determination
of $P(\nu_{\mu} \rightarrow \nu_{\mu})$ and $P(\nu_{\mu} \rightarrow \nu_{e})$
is presented by using the NOvA data. It is shown in our analysis that
$\lsim$5\% (8\%) measurement of $\tau$ neutrino appearance probability in
neutrino (antineutrino) mode is possible in the peak region $1.5 \lesssim E_\nu
\lesssim 2.5$ GeV. The $\nu$SM-independent nature of determination of the
probabilities is emphasized.
- Neutrino Interaction Physics in Neutrino Telescopes
2109.04430 [abs] [pdf]
[abstract]
by Teppei Katori, Juan Pablo Yanez, and Tianlu Yuan.
Neutrino telescopes can observe neutrino interactions starting at GeV
energies by sampling a small fraction of the Cherenkov radiation produced by
charged secondary particles. These experiments instrument volumes massive
enough to collect substantial samples of neutrinos up to the TeV scale as well
as small samples at the PeV scale. This unique ability of neutrino telescopes
has been exploited to study the properties of neutrino interactions across
energies that cannot be accessed with man-made beams. Here we present the
methods and results obtained by IceCube, the most mature neutrino telescope in
operation, and offer a glimpse of what the future holds in this field.
- Heavy neutral leptons below the kaon mass at hodoscopic detectors
2109.03831 [abs] [pdf]
[abstract]
by Carlos A. Argüelles, Nicolò Foppiani, and Matheus Hostert.
Heavy neutral leptons ($N$) below the kaon mass are severely constrained by
cosmology and lab-based searches for their decays in flight. If $N$ interacts
via an additional force, $N\to\nu e^+e^-$ decays are enhanced and cosmological
limits can be avoided. We show that the T2K and MicroBooNE neutrino experiments
provide the best limits on the mixing of $N$ with muon-neutrinos, outperforming
past-generation experiments, previously thought to dominate. We constrain
models with electromagnetically-decaying and long-lived $N$, such as in a
transition-magnetic-moment portal and in a leptophilic axion-like particle
portal, invoked to explain the MiniBooNE excess. By considering these models as
representative examples, our results show that explanations of the MiniBooNE
excess that involve $e^+e^-$ pairs from long-lived particles are in tension
with T2K, PS191, and MicroBooNE data. Similarly, these searches also constrain
MiniBooNE explanations based on single photons due to the associated $e^+e^-$
decay mode via a virtual photon.
- Constraining the neutrino mass using a multi-tracer combination of two
galaxy surveys and CMB lensing
2109.03763 [abs] [pdf]
[abstract]
by Mario Ballardini and Roy Maartens.
Measuring the total neutrino mass is one of the most exciting opportunities
available with next-generation cosmological data sets. We study the possibility
of detecting the total neutrino mass using large-scale clustering in 21cm
intensity mapping and photometric galaxy surveys, together with CMB
information. We include the scale-dependent halo bias contribution due to the
presence of massive neutrinos, and use a multi-tracer analysis in order to
reduce cosmic variance. The multi-tracer combination of an SKAO-MID 21cm
intensity map with Stage~4 CMB dramatically shrinks the uncertainty on total
neutrino mass to $\sigma(M_\nu) \simeq 45\,$meV, using only linear clustering
information ($k_{\rm max} = 0.1\, h/$Mpc) and without a prior on optical depth.
When we add to the multi-tracer the clustering information expected from LSST,
the forecast is $\sigma(M_\nu) \simeq 12\,$meV.
- Mass Composition of UHECRs from $X_{\rm max}$ Distributions Recorded by
the Pierre Auger and Telescope Array Observatories
2109.03626 [abs] [pdf]
[abstract]
by Nicusor Arsene.
In this paper we infer the mass composition of the ultra high energy cosmic
rays (UHECRs) from measurements of $X_{\rm max}$ distributions recorded at the
Pierre Auger (2014) and Telescope Array (TA) (2016) Observatories, by fitting
them with all possible combinations of Monte Carlo (MC) templates from a large
set of primary species (p, He, C, N, O, Ne, Si and Fe), as predicted by
EPOS-LHC, QGSJETII-04 and Sibyll 2.1 hadronic interaction models. We use the
individual fractions of nuclei reconstructed from one experiment in each energy
interval to build equivalent MC $X_{\rm max}$ distributions, which we compare
with the experimental $X_{\rm max}$ distributions of the other experiment,
applying different statistical tests of compatibility. The results obtained
from both experiments confirm that the mass composition of the UHECRs is
dominated ($\gtrsim$$70\%$) by protons and He nuclei {in the energy range
investigated $\lg E (\rm eV)$ = [17.8--19.3] (Auger) and $\lg E \rm (eV)$ =
[18.2--19.0] (TA).} The indirect comparisons between the $X_{\rm max}$
distributions recorded by the two experiments show that the degree of
compatibility of the two datasets is good, even excellent in some high energy
intervals, especially above the ankle ($\lg E (\rm eV) \sim 18.7$). However,
our study reveals that, at low energies, further effort in data analysis is
required in order to harmonize the results of the two experiments.
- Near-horizon microstructure and superradiant instability of black holes
2109.03376 [abs] [pdf]
[abstract]
by Rong-Zhen Guo, Chen Yuan, and Qing-Guo Huang.
Ultralight bosons, as important candidates of dark matter, can condense
around spinning black holes (BHs) to form long-lived ``boson clouds'' due to
superradiance instability. The boson-BH system can be observed through
gravitational wave detection and may become a new window to find traces of
ultr