Non-zero $\theta_{13}$ and leptonic CP phase with $A_4$ Symmetry

TL;DR

This paper presents an $A_4$ symmetry-based model explaining neutrino mixing, including non-zero $ heta_{13}$ and CP violation, consistent with experimental data and predicting observable phenomenological effects.

Contribution

The work introduces a novel $A_4$ symmetry model that accounts for neutrino mixing angles, CP violation, and lepton flavor violation within experimental bounds.

Findings

Neutrino mixing angles fit within 3σ experimental ranges.

Predicted CP phase and Jarlskog invariant suggest measurable CP violation.

Lepton flavor violating decay $$ branching ratio below current bounds.

Abstract

We consider a model based on $A_4$ symmetry to explain the phenomenon of neutrino mixing. The spontaneous symmetry breaking of $A_4$ symmetry leads to a co-bimaximal mixing matrix at leading order. We consider the effect of higher order corrections in neutrino sector and find that the mixing angles thus obtained, come well within the $3\sigma$ ranges of their experimental values. We study the implications of this formalism on the other phenomenological observables, such as CP violating phase, Jarlskog invariant and the effective Majorana mass $|M_{ee}|$. We also obtain the branching ratio of the lepton flavour violating decay $\mu\rightarrow e \gamma$ in the context of this model and find that it can be less than its present experimental upper bound.