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

TL;DR

This paper proposes a neutrino mass model based on an extended gauge symmetry and discrete symmetries, explaining atmospheric and solar neutrino deficits with specific mixing angles and mass scales.

Contribution

It introduces a see-saw model with discrete symmetries that accounts for recent neutrino oscillation data and predicts specific mixing patterns and mass scales.

Findings

Predicts maximal mu-tau neutrino mixing with sin^2 2θ = 1

Explains solar neutrino deficit with small electron-muon mixing

Identifies two mass scales for electroweak and lepton number symmetry breaking

Abstract

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 $\nu_{\mu}$ and $\nu_{\tau}$ with $sin^{2}2{\theta_{\mu\tau}}$ = 1 as required by the atmospheric neutrino data and small mixing between $\nu_{e}$ and $\nu_{\mu}$ with $sin^{2}2{\theta_{e\mu}} \sim (10^{-2}-10^{-3})$ 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.