Deviation from tri-bimaximal neutrino mixing in A4 flavor symmetry

TL;DR

This paper examines how deviations from tri-bimaximal neutrino mixing arise within the A4 flavor symmetry model, focusing on numerical analysis of mixing angles, CP violation, and neutrino mass implications.

Contribution

It provides a detailed numerical study of deviations from tri-bimaximal mixing in the A4 model, highlighting the effects of flavon vacuum alignment corrections.

Findings

heta_{23}^2 ext{ deviates little from 1

heta_{12}^2 ext{ can significantly deviate from 1/3

heta_{13} ext{ can approach current experimental bounds

Abstract

The tri-bimaximal mixing is a good approximation for the present data of neutrino mixing angles. The deviation from the tri-bimaximal mixing is discussed numerically in the framework of the A4 model. Values of \tan^2\theta_{12}, \sin^2 2\theta_{23} and |U_{e3}| deviate from the tri-bimaximal mixing due to the corrections of the vacuum alignment of flavon fields. It is remarked that \sin^2 2\theta_{23} deviates scarcely from 1 while \sin^2\theta_{12} can deviate from 1/3 considerably and \sin\theta_{13} could be near the present experimental upper bound. The CP violating measure J_{CP} and the effective Majorana neutrino mass m_{ee} are also discussed.