Broken S3 Symmetry in the Neutrino Mass Matrix and Non-Zero theta_{13}

TL;DR

This paper explores how breaking S3 symmetry in the neutrino mass matrix can explain non-zero theta_{13} and CP violation, aligning with recent experimental findings and predicting observable effects in neutrinoless double beta decay.

Contribution

It introduces a novel perturbation scheme breaking S3 symmetry to account for realistic neutrino mixing angles and CP violation, extending previous symmetric models.

Findings

Reproduces large reactor mixing angle consistent with T2K results.

Predicts a large effective neutrino mass testable in neutrinoless double beta decay.

Demonstrates that symmetry breaking induces CP violation in neutrino oscillations.

Abstract

We study the effects of breaking S3 symmetry in the neutrino mass matrix for the masses and mixing matrix of neutrinos. At zeroth order the model gives degenerate neutrino masses and accommodates tribimaximal mixing. We introduce perturbations in terms of a small and complex parameter. The perturbations are introduced in a manner such that the S3 symmetry is broken by its elements in the same representation. Successive perturbations introduce mass splitting, sizable non-zero reactor mixing angle and CP violation. This scheme of breaking S3 symmetry can reproduce a relatively large reactor mixing angle as suggested by the recent T2K results. The effective neutrino mass is predicted to be large which is testable in the ongoing and forthcoming neutrinoless double beta decay experiments.