Neutrino Mixing Phenomenology: $A_4$ Discrete Flavor Symmetry with Type-I Seesaw Mechanism

TL;DR

This paper develops a neutrino mass model based on $A_4$ symmetry and type-I seesaw, explaining nonzero $ heta_{13}$, predicting CP phases, and analyzing implications for neutrinoless double beta decay.

Contribution

It introduces a novel $A_4$ flavor symmetry model with extra flavons that accounts for observed neutrino mixing angles and predicts CP phases, linking theoretical structure with experimental data.

Findings

Nonzero $ heta_{13}$ consistent with experiments

Predicted Dirac CP-phase and Jarlskog parameter

Normal hierarchy favored over inverted hierarchy

Abstract

We study a neutrino mass model with $A_4$ discrete flavor symmetry using a type-I seesaw mechanism. The inclusion of extra flavons in our model leads to the deviations from exact tribimaximal mixing pattern resulting in a nonzero $\theta_{13}$ consistent with the recent experimental results and a sum rule for light neutrino masses is also obtained. In this framework, a connection is established among the neutrino mixing angles: reactor mixing angle($\theta_{13}$), solar mixing angle($\theta_{12}$) and atmospheric mixing angle ($\theta_{23}$). This model also allows us a prediction of Dirac CP-phase and Jarlskog parameter $J$. The octant of the atmospheric mixing angle $\theta_{23}$ occupies the lower octant. Our model prefers normal hierarchy (NH) than inverted hierarchy (IH). We use the parameter space of our model of neutrino masses to study the neutrinoless double beta decay parameter $m_{ee}$. Keywords: Discrete flavor symmetry, Type-I seesaw mechanism, Tribimaximal mixing, Dirac CP-phase, Jarlskog parameter, Neutrinoless double beta decay