scholarly journals The SO(10)-inspired leptogenesis timely opportunity

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Pasquale Di Bari ◽  
Rome Samanta
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Lower Bounds ◽  
Neutrinoless Double Beta Decay ◽  
Mass Scale ◽  
Double Beta Decay ◽  
Neutrino Masses ◽  
Neutrino Mixing ◽  
Mixing Parameters ◽  
Absolute Neutrino Mass

Abstract We study the connection between absolute neutrino mass and neutrino mixing parameters within SO(10)-inspired leptogenesis. We show that current favoured values of the unknown neutrino mixing parameters point toward values of the absolute neutrino mass scale that will be fully tested by cosmological observations and neutrinoless double beta decay experiments during next years. In particular, for mD2/mcharm≤ 5, where mD2 is the intermediate Dirac neutrino mass, and for current best fit values of the Dirac phase δ and the atmospheric mixing angle θ23, we derive a lower bound on the neutrinoless double beta decay effective neutrino mass mee ≳ 31 meV and on the sum of the neutrino masses Σimi ≳ 125 meV. These lower bounds hold for normally ordered neutrino masses, as currently favoured by global analyses, and approximately for δ ∈ [155°, 240°] and θ23 in the second octant. If values in this region will be confirmed by future planned long baseline experiments, then a signal at next generation neutrinoless double beta decay experiments is expected, despite neutrino masses being normally ordered. Outside the region, the lower bounds strongly relax but a great fraction of the allowed range of values still allows a measurement of the lightest neutrino mass. Therefore, in the next years low energy neutrino experiments will provide a stringent test of SO(10)-inspired leptogenesis, that might result either in severe constraints or in a strong evidence.

NEUTRINOLESS DOUBLE BETA DECAY

2012 ◽  
Vol 12 ◽  
pp. 80-89
Author(s):  
OLIVIERO CREMONESI
Keyword(s):  
Beta Decay ◽  
Present Status ◽  
Neutrinoless Double Beta Decay ◽  
Mass Scale ◽  
Present Knowledge ◽  
Double Beta Decay ◽  
Neutrino Masses ◽  
Mixing Parameters ◽  
Absolute Mass ◽  
Practical Tool

Neutrinoless double beta decay (ββ(0ν)) is presently the only practical tool for probing the character of neutrinos. In case neutrinos are Majorana particles ββ(0ν) can provide also fundamental informations on their absolute mass scale. The present status of experiments searching for ββ(0ν) is reviewed and the most relevant results discussed. A possibility to observe ββ(0ν) at a neutrino mass scale in the range 10-50 meV looks possible according to our present knowledge of the neutrino masses and mixing parameters. A review of the future projects and of the most relevant parameters contributing to the experimental sensitivity iss finally outlined.

DOUBLE BETA DECAY: EXPERIMENT AND THEORY

2006 ◽  
Vol 21 (08n09) ◽  
pp. 1887-1900 ◽  
Author(s):  
OLIVIERO CREMONESI
Keyword(s):  
Neutrino Physics ◽  
Beta Decay ◽  
Neutrinoless Double Beta Decay ◽  
Mass Scale ◽  
Present Knowledge ◽  
Double Beta Decay ◽  
Neutrino Masses ◽  
Mixing Parameters ◽  
Real Challenge ◽  
Double Beta Decay Experiment

The present status of experiments searching for neutrinoless double-beta decay (ββ(0ν)) is reviewed and the results of the most sensitive experiments discussed. Phenomenological aspects of ββ(0ν) are introduced and most relevant aspects for neutrino physics discussed. Given the observation of neutrino oscillations and the present knowledge of neutrino masses and mixing parameters, a possibility to observe ββ(0ν) at a neutrino mass scale mν ≈10-50 meV could actually exist. The achievement of the required experimental sensitivity is a real challenge faced by a number of new proposed projects. A review of the most relevant of them is given.

scholarly journals CONSTRAINTS ON TeV SCALE MAJORANA NEUTRINO PHENOMENOLOGY FROM THE VACUUM STABILITY OF THE HIGGS

2013 ◽  
Vol 28 (11) ◽  
pp. 1350032 ◽  
Author(s):  
JOYDEEP CHAKRABORTTY ◽  
MOUMITA DAS ◽  
SUBHENDRA MOHANTY
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Stability Condition ◽  
Branching Ratio ◽  
Neutrinoless Double Beta Decay ◽  
Majorana Neutrino ◽  
Double Beta Decay ◽  
Heavy Neutrino ◽  
Neutrino Mixing ◽  
Vacuum Stability

The vacuum stability condition of the Standard Model (SM) Higgs potential with mass in the range of 124–127 GeV puts an upper bound on the Dirac mass of the neutrinos. We study this constraint with the right-handed neutrino masses up to TeV scale. The heavy neutrinos contribute to ΔL = 2 processes like neutrinoless double beta decay and same-sign-dilepton (SSD) production in the colliders. The vacuum stability criterion also restricts the light-heavy neutrino mixing and constrains the branching ratio (BR) of lepton flavor-violating process, like μ→eγ mediated by the heavy neutrinos. We show that neutrinoless double beta decay with a lifetime ~1025 years can be observed if the lightest heavy neutrino mass is <4.5 TeV. We show that the vacuum stability condition and the experimental bound on μ→e γ together put a constrain on heavy neutrino mass MR>3.3 TeV. Finally we show that the observation of SSDs associated with jets at the LHC needs much larger luminosity than available at present. We have estimated the possible maximum cross-section for this process at the LHC and show that with an integrated luminosity 100 fb-1 it may be possible to observe the SSD signals as long as MR < 400 GeV.

scholarly journals Can the Majorana Neutrino CP-Violating Phases be Restricted?

2003 ◽  
Vol 18 (26) ◽  
pp. 1803-1808 ◽  
Author(s):  
Koichi Matsuda ◽  
Takeshi Fukuyama ◽  
Hiroyuki Nishiura
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Majorana Neutrino ◽  
Double Beta Decay ◽  
Neutrino Masses ◽  
Mixing Parameters ◽  
Double Beta Decay Experiment

We reanalyze the constraints in neutrino masses and MNS lepton mixing parameters using the new data from the terrestrial (KamLAND) and astrophysical (WMAP) observations together with the Heidelberg–Moscow double beta decay experiment. It leads us to the almost degenerate or inverse hierarchy neutrino mass scenario. We discuss the possibility of getting the bound for the Majorana CP-violating phase.

scholarly journals Super-Kamiokande neutrino oscillations and the supersymmetric model

2020 ◽  
Vol 9 ◽  
pp. 14
Author(s):  
A. Faessler
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Electron Neutrino ◽  
Tree Level ◽  
Supersymmetric Model ◽  
Neutrino Masses ◽  
Muon Neutrinos

The standard model predicts a ratio of 2 for the number of atmospheric muon to electron neutrinos, while super-Kamiokande and others measure a much smaller value (1.30±0.02 for super-Kamiokande). Super-Kamiokande is also able to measure roughly the direction and the energy of the neutrinos. The zenith-angle dependence for the muon neutrinos suggests that the muon neutrinos oscillate into a third neutrino species, either into the r neutrino or a sterile neutrino. This finding is inves- tigated within the supersymmetric model. The neutrinos mix with the neutralinos, this meaning the wino, the bino and the two higgsinos. The 7 x 7 mass matrix is calculated on the tree level. One finds that the mass matrix has three linearly dependent rows, which means that two masses are zero. They are identified with the two lightest neutrino masses. The fit of the super-Kamiokande data to oscillations between three neutrinos yields, together with the result of supersymmetry, that the third neutrino mass lies between 2x10^-2 and 10^-1 eV. The two lightest neutrino masses are in supersymmetry on the tree level zero. The averaged electron neutrino mass which is the essential parameter in the neutrinoless double-beta decay is given by {m_ve) ~ m_v3 P_ze < 0.8 x10^-2 eV (95% confidence limit). It is derived from the super-Kamiokande data in this supersymmetric model to be two orders smaller than the best value (1 eV) from the neutrinoless double-beta decay.

scholarly journals Oscillating Neutrinos and Majorana Neutrino Masses

Universe ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 29
Author(s):  
Harald Fritzsch
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Neutrinoless Double Beta Decay ◽  
Majorana Neutrino ◽  
Double Beta Decay ◽  
Neutrino Masses ◽  
Quark Masses ◽  
Mass Matrices ◽  
The Matrix ◽  
Flavor Mixing

We discuss the mass matrices with texture zeros for the quarks and leptons. The flavor mixing angles for the quarks are functions of the quark masses and can be calculated. The results agree with the experimental data. The texture zero mass matrices for the leptons and the see-saw mechanism are used to derive relations between the matrix elements of the lepton mixing matrix and the ratios of the neutrino masses. Using the measured neutrino mass differences, the neutrino masses can be calculated. The neutrinoless double beta decay is discussed. The effective Majorana neutrino mass, describing the neutrinoless double beta decay, can be calculated—it is about 4.6 meV. The present experimental limit is at least twenty times larger.

Cobimaximal neutrino mixing in the U(1)B−L extension with A4 symmetry

2020 ◽  
Vol 35 (38) ◽  
pp. 2050311
Author(s):  
V. V. Vien
Keyword(s):  
Beta Decay ◽  
Atmospheric Neutrino ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Tree Level ◽  
Physical Parameters ◽  
Neutrino Masses ◽  
Type I ◽  
Neutrino Mixing ◽  
Best Fit

We propose a renormalizable [Formula: see text] extension of the Standard model with [Formula: see text] symmetry that leads to the successful cobimaximal lepton mixing ansatz, thus providing a predictive explanation for leptonic mixing observables. The smallness of the active neutrino masses and neutrino masses ordering are produced by the type-I seesaw mechanism at the tree-level. The obtained physical parameters are well consistent with the global fit of neutrino oscillation.1 The model is predictive in the sense that it reproduces the experimental values of neutrino parameters in which the reactor neutrino mixing angle [Formula: see text] get the best-fit value and the solar and atmospheric neutrino mixing angles have little deviations from the best-fit values given in Ref. 1, however, they are consistent with the other experimental results.[Formula: see text] The effective neutrino masses governing the neutrinoless double beta decay is predicted to be [Formula: see text] for normal hierarchy and [Formula: see text] for inverted hierarchy which are well consistent with the recent experimental limits on neutrinoless double beta decay.

Neutrino mass and mixing in the 3-3-1 model with neutral leptons based on D4flavor symmetry

2014 ◽  
Vol 29 (23) ◽  
pp. 1450122 ◽  
Author(s):  
V. V. Vien
Keyword(s):  
Gauge Symmetry ◽  
Beta Decay ◽  
Neutrino Mass ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Neutrino Masses ◽  
Neutrino Mass And Mixing ◽  
Fermion Masses ◽  
Fermion Fields ◽  
Mixing Matrix

We propose a new D4flavor model based on SU (3)C⊗ SU (3)L⊗ U (1)Xgauge symmetry responsible for fermion masses and mixings in which all fermion fields act only as singlets under D4which differs from our previous work. The neutrinos get small masses from two SU (3)Lanti-sextets and one SU (3)Ltriplet which are all in singlets under D4. If a SU (3)LHiggs triplet, lying in [Formula: see text] under D4, is considered as a perturbation the corresponding neutrino mass mixing matrix gets the most general form. In this case, the model can fit the most recent data on neutrino masses and mixing with nonzero θ13. Our results show that the neutrino masses are naturally small. The sum of three light neutrino masses and the effective mass governing neutrinoless double beta decay are obtained that are consistent with the recent data.

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