scholarly journals NEUTRINO MIXING IN A DEMOCRATIC SEESAW MASS MATRIX MODEL

1996 ◽  
Vol 11 (36) ◽  
pp. 2849-2859 ◽  
Author(s):  
YOSHIO KOIDE

On the basis of a seesaw-type mass matrix model for quarks and leptons, [Formula: see text] where mL∝mR are universal for f=u, d, v and e (up-quark, downquark, neutrino and charged lepton sectors respectively), and MF has a form [(unit matrix)+(democratic-type matrix)], neutrino masses and mixings are investigated. We try to understand a large vµ−vτ mixing, i.e. sin2 2θ23~1, with mv1 ≪ mv2~mv3, which has been suggested by the atmospheric neutrino data.

2013 ◽  
Vol 28 (39) ◽  
pp. 1350184
Author(s):  
RENATA JORA ◽  
JOSEPH SCHECHTER ◽  
M. NAEEM SHAHID

We obtain analytical formulas which connect the neutrino masses and the leptonic mixing matrix with the entries in the mass matrix for the approximation in which the charged lepton mixing matrix is the unit matrix. We also extract the CP violation phase and determine the conditions in which this is present.


1997 ◽  
Vol 12 (16) ◽  
pp. 1175-1184 ◽  
Author(s):  
Kyungsik Kang ◽  
Sin Kyu Kang ◽  
Jihn E. Kim ◽  
Pyungwon Ko

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.


2000 ◽  
Vol 15 (25) ◽  
pp. 3967-3991
Author(s):  
DAIJIRO SUEMATSU

We propose a neutrino mass matrix model in which five neutrino species remain light through the seesaw mechanism within a supersymmetric 3νL+3νR framework. We construct such a model based on the nonrenormalizable terms in the superpotential constrained by the discrete symmetry which may be expected in the models at the high energy scale such as superstring. We study the possible oscillation phenomena by fixing mass parameters so as to explain the solar and atmospheric neutrino deficits and also include a candidate of the suitable dark matter. We also discuss the charged lepton mass matrix based on this neutrino model. LSND results may be consistently explained within this model.


1995 ◽  
Vol 10 (04) ◽  
pp. 289-294 ◽  
Author(s):  
HIDEO FUSAOKA ◽  
YOSHIO KOIDE

A quark mass matrix model [Formula: see text] is proposed where [Formula: see text] and Oq is a unit matrix plus a rank-one matrix. Up- and down-quark mass matrices Mu and Md are described in terms of charged lepton masses and additional three parameters (one in Mu and two in Md). The model can predict reasonable quark mass ratios (not only mu/mc, mc/mt, md/ms and ms/mb, but also mu/md) and Kobayashi–Maskawa matrix elements.


2015 ◽  
Vol 30 (32) ◽  
pp. 1550169
Author(s):  
Asan Damanik

The bimaximal (BM) neutrino mixing matrix was formulated in order to accommodate the data of the experimental results which indicate that both solar and atmospheric neutrino oscillation in vacuum are near maximal. But, after the T2K and Daya Bay Collaborations reported that the mixing angle [Formula: see text] is nonzero and relatively large, many authors have modified the neutrino mixing matrix in order to accommodate experimental data. We modified the BM mixing matrix by introducing a simple perturbation matrix into BM mixing matrix. The modified BM mixing matrix can proceed the mixing angles which are compatible with the global fit analysis data and by imposing the [Formula: see text]–[Formula: see text] symmetry into mass matrix from modified BM, we have the neutrino mass in normal hierarchy (NH): [Formula: see text]. Using the neutrino masses that obtained from neutrino mass matrix in the scheme of modified BM and imposing the constraint exact [Formula: see text] symmetry into neutrino mass matrix, we cannot have compatible squared-mass differences for both [Formula: see text] and [Formula: see text] as dictated by experimental results. In order to proceed the neutrino masses that can predict correctly the squared-mass difference, we introduce a small parameter [Formula: see text] into neutrino mass matrix. The obtained neutrino masses are in agreement with the squared-mass difference as dictated by experimental results. The predicted neutrino effective mass: [Formula: see text] in this paper can be tested in the future neutrinoless double beta decay.


2003 ◽  
Vol 18 (22) ◽  
pp. 3971-3979 ◽  
Author(s):  
S.M. BARR

A brief review is given of some ideas for explaining neutrino masses and mixings within the context of supersymmetric grand unification. Emphasis is put on so-called lopsided models.


1994 ◽  
Vol 09 (02) ◽  
pp. 169-179 ◽  
Author(s):  
R. FOOT

We re-examine neutrino oscillations in exact parity models. Previously it was shown in a specific model that large neutrino mixing angles result. We show here that this is a general result of neutrino mixing in exact parity models provided that the neutrino mass matrix is real. In this case, the effects of neutrino mixing in exact parity models is such that the probability of a given weak eigenstate remaining in that eigenstate averages to less than half when averaged over many oscillations. This result is interesting in view of the accumulating evidence for a significant deficit in the number of solar neutrinos. It may also be of relevance to the atmospheric neutrino anomaly.


2013 ◽  
Vol 2013 (5) ◽  
Author(s):  
David Marzocca ◽  
S. T. Petcov ◽  
Andrea Romanino ◽  
M. C. Sevilla

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Madan Singh

We have studied that the implication of a large value of the effective Majorana neutrino mass in case of neutrino mass matrices has either two equal elements and one zero element (popularly known as hybrid texture) or two equal cofactors and one zero minor (popularly known as inverse hybrid texture) in the flavor basis. In each of these cases, four out of sixty phenomenologically possible patterns predict near maximal atmospheric neutrino mixing angle in the limit of large effective Majorana neutrino mass. This feature remains irrespective of the experimental data on solar and reactor mixing angles. In addition, we have also performed the comparative study of all the viable cases of hybrid and inverse hybrid textures at 3σ CL.


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