29 research outputs found
High-energy constraints from low-energy neutrino non-standard interactions
Many scenarios of new physics predict the existence of neutrino Non-Standard
Interactions, new vector contact interactions between neutrinos and first
generation fermions beyond the Standard Model. We obtain model-independent
constraints on the Standard Model Effective Field Theory at high energies from
bounds on neutrino non-standard interactions derived at low energies. Our
analysis explores a large set of new physics scenarios and includes full
one-loop running effects below and above the electroweak scale. Our results
show that neutrino non-standard interactions already push the scale of new
physics beyond the TeV. We also conclude that bounds derived by other
experimental probes, in particular by low-energy precision measurements and by
charged lepton flavor violation searches, are generally more stringent. Our
study constitutes a first step towards the systematization of phenomenological
analyses to evaluate the impact of neutrino Non-Standard Interactions for new
physics scenarios at high energies.Comment: 25 pages, 7 figures, 2 tables. Merry Christmas and happy new year
CPT and CP, an entangled couple
Even though it is undoubtedly very appealing to interpret the latest T2K
results as evidence of CP violation, this claim assumes CPT conservation in the
neutrino sector to an extent that has not been tested yet. As we will show, T2K
results are not robust against a CPT-violating explanation. On the contrary, a
CPT-violating CP-conserving scenario is in perfect agreement with current
neutrino oscillation data. Therefore, to elucidate whether T2K results imply CP
or CPT violation is of utter importance. We show that, even after combining
with data from NOA and from reactor experiments, no claims about CP
violation can be made. Finally, we update the bounds on CPT violation in the
neutrino sector.Comment: 8 pages, 6 figure
Probing new neutral gauge bosons with CEvNS and neutrino-electron scattering
The potential for probing extra neutral gauge boson mediators ()
from low-energy measurements is comprehensively explored. Our study mainly
focuses on mediators present in string-inspired models and
left-right symmetry. We estimate the sensitivities of coherent-elastic
neutrino-nucleus scattering (CENS) and neutrino-electron scattering
experiments. Our results indicate that such low-energy high-intensity
measurements can provide a valuable probe, complementary to high-energy
collider searches and electroweak precision measurements.Comment: notation improved, analysis updated, conclusions unchanged, matches
published version in PR
Where we are on : addendum to "Global neutrino data and recent reactor fluxes: status of three-flavour oscillation parameters"
In this addendum to arXiv:1103.0734 we consider the recent results from
long-baseline searches at the T2K and MINOS experiments and
investigate their implications for the mixing angle and the
leptonic Dirac CP phase . By combining the indication for a
non-zero value of coming from T2K data with global neutrino
oscillation data we obtain a significance for of about
with best fit points for normal
(inverted) neutrino mass ordering. These results depend somewhat on assumptions
concerning the analysis of reactor neutrino data.Comment: 5 pages, 2 figures and 1 tabl
Neutrino Mass Ordering from Oscillations and Beyond: 2018 Status and Future Prospects
The ordering of the neutrino masses is a crucial input for a deep understanding of flavor physics, and its determination may provide the key to establish the relationship among the lepton masses and mixings and their analogous properties in the quark sector. The extraction of the neutrino mass ordering is a data-driven field expected to evolve very rapidly in the next decade. In this review, we both analyse the present status and describe the physics of subsequent prospects. Firstly, the different current available tools to measure the neutrino mass ordering are described. Namely, reactor, long-baseline (accelerator and atmospheric) neutrino beams, laboratory searches for beta and neutrinoless double beta decays and observations of the cosmic background radiation and the large scale structure of the universe are carefully reviewed. Secondly, the results from an up-to-date comprehensive global fit are reported: the Bayesian analysis to the 2018 publicly available oscillation and cosmological data sets provides strong evidence for the normal neutrino mass ordering vs. the inverted scenario, with a significance of 3.5 standard deviations. This preference for the normal neutrino mass ordering is mostly due to neutrino oscillation measurements. Finally, we shall also emphasize the future perspectives for unveiling the neutrinomass ordering. In this regard, apart from describing the expectations from the aforementioned probes, we also focus on those arising from alternative and novel methods, as 21 cm cosmology, core-collapse supernova neutrinos and the direct detection of relic neutrinos
Updated CMB and x- and gamma-ray constraints on Majoron dark matter
The Majoron provides an attractive dark matter candidate, directly associated with the mechanism responsible for spontaneous neutrino mass generation within the standard model SU(3)⊠- SU(2)⊠- U(1) framework. Here we update the cosmological and astrophysical constraints on Majoron dark matter coming from the cosmic microwave background and a variety of x- and γ-ray observations
Neutrino mass and mass ordering: No conclusive evidence for normal ordering
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 (i.e. moderate
evidence), mostly driven by neutrino oscillation data.Comment: 10 pages, 4 figure
Geotomography with solar and supernova neutrinos
We show how by studying the Earth matter effect on oscillations of solar and
supernova neutrinos inside the Earth one can in principle reconstruct the
electron number density profile of the Earth. A direct inversion of the
oscillation problem is possible due to the existence of a very simple analytic
formula for the Earth matter effect on oscillations of solar and supernova
neutrinos. From the point of view of the Earth tomography, these oscillations
have a number of advantages over the oscillations of the accelerator or
atmospheric neutrinos, which stem from the fact that solar and supernova
neutrinos are coming to the Earth as mass eigenstates rather than flavour
eigenstates. In particular, this allows reconstruction of density profiles even
over relatively short neutrino path lengths in the Earth, and also of
asymmetric profiles. We study the requirements that future experiments must
meet to achieve a given accuracy of the tomography of the Earth.Comment: 35 pages, 7 figures; minor textual changes in section