scholarly journals FINE STRUCTURE OF BETA DECAY END POINT SPECTRUM

2006 ◽  
Vol 21 (03) ◽  
pp. 517-531 ◽  
Author(s):  
SAMINA S. MASOOD ◽  
SALAH NASRI ◽  
JOSEPH SCHECHTER
Keyword(s):  
Fine Structure ◽  
Beta Decay ◽  
Neutrino Mass ◽  
Entire Range ◽  
Point Spectrum ◽  
Mass Matrix ◽  
Theoretical Models ◽  
Neutrino Masses ◽  
The Third ◽  
End Point

We note that the fine structure at the end point region of the beta decay spectrum is now essentially known using neutrino oscillation data, if the mass of one neutrino is specified. This may help to identify the effects of nonzero neutrino masses in future experiments. We also give a compact description of the entire range of allowed neutrino masses as a function of the third neutrino mass, m3. A three neutrino assumption is being made. An exact treatment of phase space kinematics is used, in contrast to the conventional approximate formula. This work is independent of theoretical models; however, additional restrictions due to the assumption of a "complementary ansatz" for the neutrino mass matrix are also discussed. The ansatz implies that the values of the three neutrino masses should approximately be able to form a triangle. It is noted that most of the presently allowed neutrino mass sets have this triangular property.

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 Inverted neutrino mass hierarchy and mixing in the Zee-Babu model

2016 ◽  
Vol 25 (4) ◽  
pp. 291
Author(s):  
Vo Van Vien ◽  
Hoang Ngoc Long ◽  
Phan Ngoc Thu
Keyword(s):  
Cp Violation ◽  
Effective Mass ◽  
Beta Decay ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Double Beta Decay ◽  
Recent Analysis ◽  
Neutrino Masses ◽  
Mass Hierarchy ◽  
Neutrino Mass Hierarchy

We show that the neutrino mass matrix of the Zee-Babu model isable to fit the recent data on neutrino masses and mixingwith non-zero $\theta_{13}$ in the inverted neutrino mass hierarchy. The results show that the Majorana  phases are equal to zero and the Dirac phase ($\de$) ispredicted to either $0$ or $\pi$, i. e, there is no CP violation in the Zee-Babu model at the two loop level. The effective mass governingneutrinoless double beta decay and the sum of neutrino masses areconsistent with the recent analysis.

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 Parametrization of the Yukawa matrix in the scotogenic model and single-zero textures of the neutrino mass matrix

2019 ◽  
Vol 34 (19) ◽  
pp. 1950098 ◽  
Author(s):  
Teruyuki Kitabayashi
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Branching Ratio ◽  
Neutrino Mass Matrix ◽  
Neutrino Masses ◽  
Neutrino Sector ◽  
The One ◽  
Relic Abundance ◽  
Analytical Expressions ◽  
Data Group

As the first topic, we propose a new parametrization of the complex Yukawa matrix in the scotogenic model. The new parametrization is compatible with the particle data group parametrization of the neutrino sector. Some analytical expressions for the neutrino masses with the new parametrization are shown. As the second topic, we consider the phenomenology of the scotogenic model with the one-zero-textures of the neutrino flavor mass matrix. One of the six patterns of the neutrino mass matrix is favorable for the real Yukawa matrix. On the other hand, for the complex Yukawa matrix, five of the six patterns are compatible with observations of the neutrino oscillations, dark matter relic abundance and branching ratio of the [Formula: see text] process.

scholarly journals PERTURBED INVARIANT UNDER A CYCLIC PERMUTATION WITH TRACE OF NEUTRINO MASS MATRIX REMAIN CONSTANT

2011 ◽  
Vol 26 (08) ◽  
pp. 567-574 ◽  
Author(s):  
ASAN DAMANIK
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Cyclic Permutation ◽  
Neutrino Mass Matrix ◽  
Neutrino Masses ◽  
Inverted Hierarchy ◽  
Seesaw Mechanism ◽  
Mixing Parameters ◽  
Difference Formula ◽  
Mass Matrices

We construct a neutrino mass matrix Mν via a seesaw mechanism with perturbed invariant under a cyclic permutation by introducing a parameter δ into the diagonal elements of Mν with the assumption that trace of the perturbed Mν is equal to trace of the unperturbed Mν. We found that the perturbed neutrino mass matrices Mν can predict the mass-squared difference [Formula: see text] with the possible hierarchy of neutrino mass is normal or inverted hierarchy. By using the advantages of the mass-squared differences and mixing parameters data from neutrino oscillation experiments, we then have neutrino masses in inverted hierarchy with masses: |m1| = 0.101023 eV , |m2| = 0.101428 eV and |m3| = 0.084413 eV .

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 $$3+1$$ active–sterile neutrino mixing in $$B-L$$ model with $$S_{3}{\times Z_4\times Z_2}$$ symmetry for normal neutrino mass ordering

2021 ◽  
Vol 81 (5) ◽  
Author(s):  
V. V. Vien
Keyword(s):  
Neutrino Mass ◽  
Sterile Neutrino ◽  
Mass Matrix ◽  
Neutrino Masses ◽  
Yukawa Interaction ◽  
Neutrino Mixing ◽  
Normal Ordering ◽  
Mixing Angles ◽  
Active Mixing ◽  
Best Fit

AbstractWe propose a non-renormalizable $$B-L$$ B - L model with $$S_{3}{\times Z_4\times Z_2}$$ S 3 × Z 4 × Z 2 symmetry which successfully accommodates the current active–sterile neutrino mixing in $$3+1$$ 3 + 1 scheme. The $$S_3$$ S 3 flavor symmetry is supplemented by $$Z_4\otimes Z_2$$ Z 4 ⊗ Z 2 symmetry to consolidate the Yukawa interaction of the model. The presence of $$S_3\otimes Z_4\otimes Z_2$$ S 3 ⊗ Z 4 ⊗ Z 2 flavour symmetry plays an important role in generating the desired structure of the neutrino mass matrix. The model can reproduce the recent observed active-neutrino neutrino oscillation data for normal ordering in which two sterile–active mixing angles $$\theta _{14, 24}$$ θ 14 , 24 get the best-fit values and the obtained values of $$\theta _{34}, \delta _{14}, \delta _{14}$$ θ 34 , δ 14 , δ 14 , the sum of neutrino mass and the effective neutrino masses are within their currently allowed ranges.

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.

scholarly journals BOUNDS FOR NEUTRINOLESS DOUBLE BETA DECAY IN SO(10) INSPIRED SEESAW MODELS

2004 ◽  
Vol 19 (40) ◽  
pp. 2993-3000 ◽  
Author(s):  
F. BUCCELLA ◽  
D. FALCONE
Keyword(s):  
Gauge Theory ◽  
Matrix Element ◽  
Beta Decay ◽  
Neutrino Mass ◽  
Quark Mass ◽  
Mass Matrix ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Up Quark ◽  
The Matrix

By requiring the lower limit for the lightest right-handed neutrino mass, obtained in the baryogenesis from leptogenesis scenario, and a Dirac neutrino mass matrix similar to the up-quark mass matrix, we predict small values for the νe mass and for the matrix element mee responsible of the neutrinoless double beta decay, mνe around 5×10-3 eV and mee smaller than 10-3 eV , respectively. The allowed range for the mass of the heaviest right-handed neutrino is centered around the value of the scale of B–L breaking in the SO (10) gauge theory with Pati–Salam intermediate symmetry.

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