3,393 research outputs found
Searches for new physics at the Hyper-Kamiokande experiment
We investigate the ability of the upcoming Hyper-Kamiokande (Hyper-K)
neutrino experiment to detect new physics phenomena beyond the standard,
three-massive-neutrinos paradigm; namely the existence of a fourth, sterile
neutrino or weaker-than-weak, non-standard neutrino interactions. With both
beam-based neutrinos from the Japan Proton Accelerator Research Complex
(J-PARC) and atmospheric neutrinos, Hyper-K is capable of exploring new ranges
of parameter space in these new-physics scenarios. We find that Hyper-K has
comparable capability to the upcoming Deep Underground Neutrino Experiment
(DUNE), and that combining both beam- and atmospheric-based data can clear up
degeneracies in the parameter spaces of interest. We also comment on the
potential improvement in searches for new physics if a combined analysis were
performed using Hyper-K and DUNE data.Comment: 14 pages, 8 figures. Minor changes to results; matches published
versio
Proton Fixed-Target Scintillation Experiment to Search for Minicharged Particles
We propose a low-cost and movable setup to probe minicharged particles (or
milli-charged particles) using high-intensity proton fixed-target facilities.
This proposal, FerMINI, consists of a milliQan-type detector, requiring
multi-coincident (nominally, triple-coincident) scintillation signatures within
a small time window, located downstream of the proton target of a neutrino
experiment. During the collisions of a large number of protons on the target,
intense minicharged particle beams may be produced via meson photo-decays and
Drell-Yan production. We take advantage of the high statistics, shielding, and
potential neutrino-detector-related background reduction to search for
minicharged particles in two potential sites: the MINOS near detector hall and
the proposed DUNE near detector hall, both at Fermilab. We also explore several
alternative designs, including the modifications of the nominal detector to
increase signal yield, and combining this detector technology with existing and
planned neutrino detectors to better search for minicharged particles. The CERN
SPS beam and associated experimental structure also provide a similar
alternative. FerMINI can achieve unprecedented sensitivity for minicharged
particles in the MeV to few GeV regime with fractional charge
between (potentially saturating the
detector limitation) and .Comment: A spelling error corrected, 10 pages, 2 figure
Neutrino vs. Antineutrino Oscillation Parameters at DUNE and Hyper-Kamiokande
Testing, in a non-trivial, model-independent way, the hypothesis that the
three-massive-neutrinos paradigm properly describes nature is among the main
goals of the current and the next generation of neutrino oscillation
experiments. In the coming decade, the DUNE and Hyper-Kamiokande experiments
will be able to study the oscillation of both neutrinos and antineutrinos with
unprecedented precision. We explore the ability of these experiments, and
combinations of them, to determine whether the parameters that govern these
oscillations are the same for neutrinos and antineutrinos, as prescribed by the
CPT-theorem. We find that both DUNE and Hyper-Kamiokande will be sensitive to
unexplored levels of leptonic CPT-violation. Assuming the parameters for
neutrino and antineutrinos are unrelated, we discuss the ability of these
experiments to determine the neutrino and antineutrino mass-hierarchies,
atmospheric-mixing octants, and CP-odd phases, three key milestones of the
experimental neutrino physics program. Additionally, if the CPT-theorem is
violated in nature in a way that is consistent with all present neutrino and
antineutrino oscillation data, we find that DUNE and Hyper-Kamiokande have the
potential to ultimately establish CPT-invariance violation.Comment: 14 pages, 6 figure
Non-standard Neutrino Interactions at DUNE
We explore the effects of non-standard neutrino interactions (NSI) and how
they modify neutrino propagation in the Deep Underground Neutrino Experiment
(DUNE). We find that NSI can significantly modify the data to be collected by
the DUNE experiment as long as the new physics parameters are large enough. For
example, If the DUNE data are consistent with the standard
three-massive-neutrinos paradigm, order 0.1 (in units of the Fermi constant)
NSI effects will be ruled out. On the other hand, if large NSI effects are
present, DUNE will be able to not only rule out the standard paradigm but also
measure the new physics parameters, sometimes with good precision. We find
that, in some cases, DUNE is sensitive to new sources of CP-invariance
violation. We also explored whether DUNE data can be used to distinguish
different types of new physics beyond nonzero neutrino masses. In more detail,
we asked whether NSI can be mimicked, as far as the DUNE setup is concerned, by
the hypothesis that there is a new light neutrino state.Comment: 14 pages, 9 figures. Matches version submitted to journal. Bug fixed:
quantitative results changed, qualitative results and conclusions unchange
Multimessenger Astronomy and New Neutrino Physics
We discuss how to constrain new physics in the neutrino sector using
multimessenger astronomical observations by the IceCube experiment. The
information from time and direction coincidence with an identifiable source is
used to improve experimental limits by constraining the mean free path of
neutrinos from these sources. Over the coming years, IceCube is expected to
detect neutrinos from a variety of neutrino-producing sources, and has already
identified the Blazar TXS 0506+056 as a neutrino-producing source. We explore
specific phenomenological models: additional neutrino interactions,
neutrinophilic dark matter, and lepton-number-charged axion dark matter. For
each new physics scenario, we interpret the observation of neutrinos from TXS
0506+056 as a constraint on the parameters of the new physics models. We also
discuss mergers involving neutron stars and black holes, and how the detection
of neutrinos coincident with these events could place bounds on the new physics
models.Comment: 9 pages, 2 figures, matches published version. Results changed to
include pseudoanalysis of TXS 0506+056 blazar neutrino data -- resulting
limits improve
CP-Invariance Violation at Short-Baseline Experiments in 3+1 Neutrino Scenarios
New neutrino degrees of freedom allow for more sources of CP-invariance
violation (CPV). We explore the requirements for accessing CP-odd mixing
parameters in the so-called 3+1 scenario, where one assumes the existence of
one extra, mostly sterile neutrino degree of freedom, heavier than the other
three mass eigenstates. As a first step, we concentrate on the nu_e to nu_mu
appearance channel in a hypothetical, upgraded version of the nuSTORM proposal.
We establish that the optimal baseline for CPV studies depends strongly on the
value of Delta m^2_14 -- the new mass-squared difference -- and that the
ability to observe CPV depends significantly on whether the experiment is
performed at the optimal baseline. Even at the optimal baseline, it is very
challenging to see CPV in 3+1 scenarios if one considers only one appearance
channel. Full exploration of CPV in short-baseline experiments will require
precision measurements of tau-appearance, a challenge significantly beyond what
is currently being explored by the experimental neutrino community.Comment: 11 pages, 4 figures. Matches published version; results and
conclusions unchange
Origin of Sterile Neutrino Dark Matter via Vector Secret Neutrino Interactions
Secret neutrino interactions can play an essential role in the origin of dark
matter. We present an anatomy of production mechanisms for sterile neutrino
dark matter, a keV-scale gauge-singlet fermion that mixes with active
neutrinos, in the presence of a new vector boson mediating secret interactions
among active neutrinos. We identify three regimes of the vector boson's mass
and coupling where it makes distinct impact on dark matter production through
the dispersion relations and/or scattering rates. We also analyze models with
gauged and numbers which have a similar dark matter
cosmology but different vector boson phenomenology. We derive the parameter
space in these models where the observed relic abundance is produced for
sterile neutrino dark matter. They serve as well-motivated target for the
upcoming experimental searches.Comment: 29 pages, 8 figures, comments welcome. Typos fixed. Results and
conclusions unchange
Leptonic Unitarity Triangles
We present a comprehensive analysis of leptonic unitarity triangles, using
both current neutrino oscillation data and projections of next-generation
oscillation measurements. Future experiments, sensitive to the degree of CP
violation in the lepton sector, will enable the construction of precise
triangles. We show how unitarity violation could manifest in the triangles and
discuss how they serve as unitarity tests. We also propose the use of Jarlskog
factors as a complementary means of probing unitarity. This analysis highlights
the importance of testing the unitarity of the leptonic mixing matrix, an
understanding of which is crucial for deciphering the nature of the neutrino
sector.Comment: Significantly updated analysis: latest NOvA and T2K results included,
as well as future projections of IceCube-Gen2 and T2HK added. Matches version
to appear in Phys. Rev.
Hunting On- and Off-Axis for Light Dark Matter with DUNE-PRISM
We explore the sensitivity of the Deep Underground Neutrino Experiment (DUNE)
near detector and the proposed DUNE-PRISM movable near detector to sub-GeV dark
matter, specifically scalar dark matter coupled to the Standard Model via a
sub-GeV dark photon. We consider dark matter produced in the DUNE target that
travels to the detector and scatters off electrons. By combining searches for
dark matter at many off-axis positions with DUNE-PRISM, sensitivity to this
scenario can be much stronger than when performing a measurement at one on-axis
position.Comment: 16 pages (including 5 appendices), 11 figures. Version 2 matches
published version with significant rearrangement of results (results
unchanged). Version 1 contains nuclear scattering results not present in v
Constraining the Self-Interacting Neutrino Interpretation of the Hubble Tension
Large, non-standard neutrino self-interactions have been shown to resolve the
tension in Hubble constant measurements and a milder tension in
the amplitude of matter fluctuations. We demonstrate that interactions of the
necessary size imply the existence of a force-carrier with a large neutrino
coupling () and mass in the keV -- 100 MeV range. This mediator is
subject to stringent cosmological and laboratory bounds, and we find that
nearly all realizations of such a particle are excluded by existing data unless
it carries spin 0 and couples almost exclusively to -flavored neutrinos.
Furthermore, we find that the light neutrinos must be Majorana, and that a
UV-complete model requires a non-minimal mechanism to simultaneously generate
neutrino masses and appreciable self-interactions.Comment: 11 pages, 1 figure, 4 appendices. Version 2 matches published versio
- …