scholarly journals NEUTRINO PARAMETER SPACE FOR A VANISHING ee ELEMENT IN THE NEUTRINO MASS MATRIX

2007 ◽  
Vol 22 (19) ◽  
pp. 1401-1410 ◽  
Author(s):  
S. DEV ◽  
SANJEEV KUMAR
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Parameter Space ◽  
Mass Matrix ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Neutrino Mass Matrix ◽  
Majorana Mass ◽  
Texture Zero ◽  
Majorana Neutrinos

The consequences of a texture zero at the ee entry of neutrino mass matrix in the flavor basis, which also implies a vanishing effective Majorana mass for neutrinoless double beta decay, have been studied for Majorana neutrinos. The neutrino parameter space under this condition has been constrained in the light of all available neutrino data including the CHOOZ bound on [Formula: see text].

scholarly journals Seesaw model and two zero flavor neutrino texture

2017 ◽  
Vol 32 (06n07) ◽  
pp. 1750034 ◽  
Author(s):  
Teruyuki Kitabayashi ◽  
Masaki Yasuè
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Mass Formula ◽  
Mass Matrix ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Neutrino Mass Matrix ◽  
Seesaw Mechanism ◽  
Matrix Formula ◽  
Matrix Scheme

In the two zero flavor neutrino mass matrix scheme with nonvanishing Majorana effective mass [Formula: see text] for the neutrinoless double beta decay, four textures are compatible with observed data. We obtain the complete list of the possible textures of four zero Dirac neutrino mass matrix [Formula: see text] in the seesaw mechanism providing these four flavor neutrino textures. Explicit analytical analysis of [Formula: see text] turns out to provide the relation of [Formula: see text].

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.

scholarly journals IMPLICATIONS OF OBSERVED NEUTRINOLESS DOUBLE BETA DECAY

2001 ◽  
Vol 16 (38) ◽  
pp. 2469-2482 ◽  
Author(s):  
H. V. KLAPDOR-KLEINGROTHAUS ◽  
U. SARKAR
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Confidence Level ◽  
Neutrinoless Double Beta Decay ◽  
Solar Neutrinos ◽  
Double Beta Decay ◽  
Atmospheric Neutrinos ◽  
Natural Choice ◽  
Mass Matrices ◽  
Majorana Neutrinos

Recently a positive indication of the neutrinoless double beta decay has been announced. We study the implications of this result taking into consideration earlier results on atmospheric neutrinos and solar neutrinos. We also include in our discussions the recent results from SNO and K2K. We point out that on the confidence level given for the double beta signal, the neutrino mass matrices are now highly constrained. All models predicting Dirac masses are ruled out and leptogenesis becomes a natural choice. Only the degenerate and the inverted hierarchical solutions are allowed for the three-generation Majorana neutrinos. In both cases we find that the radiative corrections destabilize the solutions and the LOW, VO and Just So solutions of the solar neutrinos are ruled out. For the four-generation case only the inverted hierarchical scenario is allowed.

A STRATEGY FOR DISCOVERING HEAVY NEUTRINOS

1996 ◽  
Vol 11 (09) ◽  
pp. 1607-1611
Author(s):  
CLEMENS A. HEUSCH ◽  
PETER MINKOWSKI
Keyword(s):  
Energy Range ◽  
Beta Decay ◽  
Neutrino Mass ◽  
Particle Physics ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Mass Problem ◽  
Lepton Flavor ◽  
Majorana Neutrinos ◽  
Unique Capability

Same-sign lepton collisions in the TeV energy range may well have the unique capability to search for clear signals for the exchange of heavy Majorana neutrinos. Lepton-flavor-violating transitions e−e−→W−W− can thus contribute to the understanding of two unsolved riddles in particle physics: the neutrino mass problem and the question of the Dirac or Majorana character of heavy neutrinos. This search is not similarly accessible to such effects as neutrinoless double beta decay. The resulting experimental signatures are hard to miss.

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.

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