arXiv subjects

Asim K. Ray

Publications and source records attributed to Asim K. Ray.

4 recordsLinked to original sources

arXiv2001

Neutrino Mass Matrices in Models with Horizontal Symmetries

We have studied the most general neutrino mass matrices in models with SU(2) and SU(3) horizontal symmetries. Without going into the details of the models it is possible to write down the effective operators, which predict the structure of the Majorana neutrino mass matrices. Unlike other extensions of the standard model, the structure is now independent of the effective Yukawa couplings and depends entirely on the Higgs which gives mass to the other fermions. In the case of SU(3) symmetries the lowest dimensional operators are forbidden requiring a low mass scale for lepton number violation.

hep-ph↗

arXiv1999

An $SU(2)_{L}\times U(1)_{Y} \times S_{3} \times D$ model for atmospheric and solar neutrino deficits

Motivated by the recent Super-Kamiokande experiment on atmospheric and solar neutrino oscillation we propose a see-saw model of three generations of neutrinos based on the gauge group $SU(2)_{L}\times U(1)_{Y}$ with discrete symmetries $(S_{3} \times D)$ and three right handed singlet neutrinos so that this model can accommodate the recent Super-Kamiokande data on atmospheric and solar neutrino oscillations. The model predicts maximal mixing between $ν_μ$ and $ν_τ$ with $sin^{2}2{θ_{μτ}}$ = 1 as required by the atmospheric neutrino data and small mixing between $ν_{e}$ and $ν_μ$ with $sin^{2}2{θ_{eμ}} \sim (10^{-2}-10^{-3})$ as a possible explanation of the solar neutrino deficit through the MSW mechanism. The model admits two mass scales of which one breaks the electroweak symmetry and the other is responsible for the breaking of the lepton number symmetry at GUT scale leading to small Majorana mass of the left handed doublet neutrinos.

hep-ph↗

arXiv1995

Degenerate Dirac Neutrinos In An ${SU(2)}_L\times {U(1)}_Y$ Model With $S_3\times Z_3\times Z_4$ Discrete Symmetry

We demonstrate that almost degenerate Dirac neutrinos of mass of few eV and transition magnetic moment of the order of ${10}^{-11}$ $μ_B$ can be obtained in an ${SU(2)}_L\times {U(1)}_Y$ model with $S_3\times Z_3\times Z_4$ discrete symmetry and appropriate Higgs fields. Transition magnetic moment of the Dirac neutrino arises from to the contribution of leptons and charged Higgs fields at the one loop level.

hep-ph↗

arXiv1995

Recent Neutrino Experiments and Their Consistency In An Extended Harvard Model

We demonstrate that the solar and atmospheric neutrino data as well as the recent result of the LSND experiment cannot be satisfied simultaneously with three light neutrinos if we consider the mass degeneracy for two neutrinos in the context of an extended Harvard Model based on the gauge group $SU(2)_{qL}\times {SU(2)}_{lL}\times {U(1)}_Y$ with $S_3\times Z_4$ discrete symmetry. Assuming two different representation contents under $S_3\times Z_4$ symmetry for pairwise neutrinos and the lone neutrino the present model admits neutrino masses of the order of 2.8 eV and can fit either solar and atmospheric neutrino data or the LSND and solar neutrino data.

hep-ph↗