Non-Zero $\theta_{13}$ and $\delta_{CP}$ in a Neutrino Mass Model with $A_4$ Symmetry

TL;DR

This paper explores a neutrino mass model with $A_4$ symmetry, showing how perturbations can produce realistic mixing angles and CP violation, including non-zero $ heta_{13}$ and $ heta_{CP}$.

Contribution

It introduces $Z_2 imes Z_2$ invariant perturbations in an $A_4$ symmetric neutrino model to generate realistic mixing parameters and CP violation.

Findings

Perturbations in the charged lepton sector yield acceptable $ heta_{13}$.

Perturbations in the neutrino sector can produce maximal CP violation.

Adjusting perturbations allows for any $ heta_{CP}$ value.

Abstract

In this paper, we consider a neutrino mass model based on $A_4$ symmetry. The spontaneous symmetry breaking in this model is chosen to obtain tribimaximal mixing in the neutrino sector. We introduce $Z_2 \times Z_2$ invariant perturbations in this model which can give rise to acceptable values of $\theta_{13}$ and $\delta_{CP}$. Perturbation in the charged lepton sector alone can lead to viable values of $\theta_{13}$, but cannot generate $\delta_{CP}$. Perturbation in the neutrino sector alone can lead to acceptable $\theta_{13}$ and maximal CP violation. By adjusting the magnitudes of perturbations in both sectors, it is possible to obtain any value of $\delta_{CP}$.