GENERALIZED FUKUGITA–TANIMOTO–YANAGIDA NEUTRINO MASS ANSATZ

2007 ◽  
Vol 16 (05) ◽  
pp. 1405-1416 ◽  
Author(s):  
MIDORI OBARA ◽  
ZHI-ZHONG XING
Keyword(s):  
Beta Decay ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Neutrino Masses ◽  
Neutrino Mixing ◽  
Mixing Angles ◽  
Effective Masses ◽  
Majorana Neutrinos ◽  
Mass Degeneracy ◽  
The Masses

We generalize the Fukugita–Tanimoto–Yanagida ansatz by allowing the masses of three heavy right-handed Majorana neutrinos, Mi (i = 1,2,3), to be partially non-degenerate and search for the parameter space which can be consistent with the current neutrino oscillation data, for three non-degenerate mass cases (A) M3 = M2 ≠ M1, (B) M2 = M1 ≠ M3 and (C) M1 = M3 ≠ M2. We also examine the effect of the deviation from the complete mass degeneracy in each case. Finally, we obtain the numerical constraints on three light neutrino masses, three neutrino mixing angles and three CP-violating phases, together with the predictions for the Jarlskog invariant of CP violation and the effective masses of the tritium beta decay and the neutrinoless double-beta decay.

scholarly journals CONSTRAINTS OF MIXING ANGLES FROM LEPTON NUMBER VIOLATING PROCESSES

1999 ◽  
Vol 14 (06) ◽  
pp. 433-445 ◽  
Author(s):  
HIROYUKI NISHIURA ◽  
KOUICHI MATSUDA ◽  
TAKESHI FUKUYAMA
Keyword(s):  
Beta Decay ◽  
Neutrinoless Double Beta Decay ◽  
Lepton Number ◽  
Double Beta Decay ◽  
Neutrino Masses ◽  
Mixing Angles ◽  
Left Handed ◽  
Majorana Neutrinos ◽  
Mixing Matrix ◽  
Lepton Number Violating

We discuss the constraints of lepton mixing angles from lepton number violating processes such as neutrinoless double beta decay, μ--e+ conversion and K decay, K-→π+μ-μ- which are allowed only if neutrinos are Majorana particles. The rates of these processes are proportional to the averaged neutrino mass defined by [Formula: see text] in the absence of right-handed weak coupling. Here a, b(j) are flavor(mass) eigenstates and Uaj is the left-handed lepton mixing matrix. We give general conditions imposed on <mν>ab in terms of mi, lepton mixing angles and CP violating phases (three phases in Majorana neutrinos). These conditions are reduced to the constraints among mi, lepton mixing angles and <mν>ab which are irrelevant to the concrete values of CP phases. Given a <mν>ab experimentally, these conditions constrain mi and the lepton mixing angles. Though these constraints are still loose except for neutrinoless double beta decay, they will become helpful through rapid improvements of experiments. By using these constraints we also derive the limits on averaged neutrino masses for μ--e+ conversion and K decay, K-→π+μ-μ-, respectively. We also present the bounds for CP phases in terms of mi, mixing angles and <mν>ab.

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.

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.

scholarly journals Almost Maximally Broken Permutation Symmetry for Neutrino Mass Matrix

1997 ◽  
Vol 12 (16) ◽  
pp. 1175-1184 ◽  
Author(s):  
Kyungsik Kang ◽  
Sin Kyu Kang ◽  
Jihn E. Kim ◽  
Pyungwon Ko
Keyword(s):  
Mass Matrix ◽  
Atmospheric Neutrino ◽  
Current Data ◽  
Double Beta Decay ◽  
Neutrino Masses ◽  
Neutrino Mixing ◽  
Family Symmetry ◽  
Majorana Neutrinos ◽  
Charged Leptons ◽  
The Masses

Assuming three light neutrinos are Majorana particles, we propose mass matrix ansatz for the charged leptons and Majorana neutrinos with family symmetry S3 broken into S1 and S2, respectively. Each matrix has three parameters, which are fixed by measured charged lepton masses, differences of squared neutrino masses relevant to the solar and the atmospheric neutrino puzzles, and the masses of three light Majorana neutrinos as a candidate for hot dark matter with ∑|mν|~ 6 eV . The resulting neutrino mixing is compatible with the data for the current upper limit, <mνe> th <0.7 eV , of neutrino-less double beta decay experiments, and the current data for various types of neutrino oscillation experiments. One solution of our model predicts that νμ→ντ oscillation probability is about < 0.008 with Δm2 ~ 10-2 eV 2, which may not be accessible at CHORUS and other on-going experiments.

scholarly journals Neutrino mixing with nonzero θ13 and CP violation in the 3-3-1 model based on A4 flavor symmetry

2015 ◽  
Vol 30 (21) ◽  
pp. 1550117 ◽  
Author(s):  
Vo Van Vien ◽  
Hoang Ngoc Long
Keyword(s):  
Cp Violation ◽  
Effective Mass ◽  
Beta Decay ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Neutrino Masses ◽  
Flavor Symmetry ◽  
Neutrino Mixing ◽  
Fermion Masses ◽  
New Formula

We propose a 3-3-1 model with neutral fermions based on [Formula: see text] flavor symmetry responsible for fermion masses and mixings with nonzero [Formula: see text]. To get realistic neutrino mixing, we just add a new [Formula: see text] triplet being in [Formula: see text] under [Formula: see text]. The neutrinos get small masses from two [Formula: see text] antisextets and one [Formula: see text] triplet. The model can fit the present data on neutrino masses and mixing as well as the effective mass governing neutrinoless double beta decay. Our results show that the neutrino masses are naturally small and a little deviation from the tri-bimaximal neutrino mixing form can be realized. The Dirac CP violation phase [Formula: see text] is predicted to either [Formula: see text] or [Formula: see text] with [Formula: see text].

scholarly journals CONSTRAINTS OF MIXING ANGLES FROM NEUTRINO OSCILLATION EXPERIMENTS AND NEUTRINOLESS DOUBLE BETA DECAY

1998 ◽  
Vol 13 (28) ◽  
pp. 2279-2287 ◽  
Author(s):  
TAKESHI FUKUYAMA ◽  
KOUICHI MATSUDA ◽  
HIROYUKI NISHIURA
Keyword(s):  
Beta Decay ◽  
Neutrino Oscillation ◽  
Neutrino Mass ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Neutrino Masses ◽  
Mixing Angles

From the analyses of the recent data of neutrino oscillation experiments (especially the CHOOZ and the super-Kamiokande experiments), we discuss how these data affect the neutrinoless double beta decay ((ββ)0ν) rate and vice versa assuming that neutrinos are Majorana particles. For the case of m1~m2≪m3 (mi are neutrino masses), we obtain, from the data of the CHOOZ and super-Kamiokande, 0.28 ≲ sin 2θ23≲ 0.76 and sin 2θ13≲ 0.05. Combining the latter constraint with the analysis of the "averaged" neutrino mass <mν> appeared in (ββ)0ν, we find that [Formula: see text], which leads to the constraint on <mν> as <mν> ≲ 0.05m3 + (1 - 0.05)m2. For the case of m1≪m2~ m3, we find that the data of neutrino oscillation experiments and (ββ)0ν imply the following constraints of mixing angles: if 0.95m3≲ <mν> < m3, [Formula: see text]. If <mν> ≲ 0.95m3, [Formula: see text] and [Formula: see text].

HEAVY MAJORANA NEUTRINOS IN HIGH-ENERGY e-e- COLLISIONS COMPARED WITH THEIR EFFECTS INDUCING NEUTRINOLESS DOUBLE BETA DECAY

2000 ◽  
Vol 15 (16) ◽  
pp. 2429-2446
Author(s):  
CLEMENS A. HEUSCH ◽  
PETER MINKOWSKI
Keyword(s):  
Beta Decay ◽  
Short Range ◽  
Neutrinoless Double Beta Decay ◽  
High Energy ◽  
Double Beta Decay ◽  
Mixing Parameters ◽  
Short Range Repulsion ◽  
Energy Environment ◽  
Majorana Neutrinos ◽  
The Masses

We discuss the potential of e-e- collisions at energies comparable to the masses of heavy Majorana neutrinos to reveal their mass and mixing parameters. This potential is compared with the low-energy environment in neutrinoless double beta decay of complex nuclei. We give estimates for the short-range repulsion between any pair of valence quarks bound inside two different nucleons giving rise to suppression factors in the range of 50–100 in amplitude for decays mediated by heavy flavors.

LEPTON FLAVOR VIOLATION, LEPTOGENESIS AND NEUTRINO MIXING IN QUARK-LEPTON COMPLEMENTARITY SCENARIOS

2007 ◽  
Vol 22 (31) ◽  
pp. 5875-5888 ◽  
Author(s):  
WERNER RODEJOHANN ◽  
KATHRIN A. HOCHMUTH
Keyword(s):  
Detailed Analysis ◽  
Beta Decay ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Lepton Flavor Violation ◽  
Neutrino Mixing ◽  
Lepton Flavor ◽  
Flavor Violation

We conduct a detailed analysis of the phenomenology of two predictive see-saw scenarios which lead to the Quark-Lepton Complementarity relation θ12+θC = π/4. The neutrino mixing observables and their correlations, neutrinoless double beta decay, lepton flavor violating decays such as μ → eγ and leptogenesis are discussed. The features which allow to distinguish the scenarios are identified.

scholarly journals NEUTRINO MASSES, LEPTON FLAVOR MIXING AND LEPTOGENESIS IN THE MINIMAL SEESAW MODEL

2007 ◽  
Vol 16 (01) ◽  
pp. 1-50 ◽  
Author(s):  
WAN-LEI GUO ◽  
ZHI-ZHONG XING ◽  
SHUN ZHOU
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Majorana Neutrino ◽  
Double Beta Decay ◽  
Neutrino Mixing ◽  
Lepton Flavor ◽  
Seesaw Model ◽  
Flavor Mixing ◽  
Majorana Neutrinos

We present a review of neutrino phenomenology in the minimal seesaw model (MSM), an economical and intriguing extension of the Standard Model with only two heavy right-handed Majorana neutrinos. Given current neutrino oscillation data, the MSM can predict the neutrino mass spectrum and constrain the effective masses of the tritium beta decay and the neutrinoless double-beta decay. We outline five distinct schemes to parameterize the neutrino Yukawa-coupling matrix of the MSM. The lepton flavor mixing and baryogenesis via leptogenesis are investigated in some detail by taking account of possible texture zeros of the Dirac neutrino mass matrix. We derive an upper bound on the CP-violating asymmetry in the decay of the lighter right-handed Majorana neutrino. The effects of the renormalization-group evolution on the neutrino mixing parameters are analyzed, and the correlation between the CP-violating phenomena at low and high energies is highlighted. We show that the observed matter-antimatter asymmetry of the Universe can naturally be interpreted through the resonant leptogenesis mechanism at the TeV scale. The lepton-flavor-violating rare decays, such as μ→e+γ, are also discussed in the supersymmetric extension of the MSM.

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