Model for T2K indication with maximal atmospheric angle and tri-maximal solar angle

TL;DR

This paper explores a neutrino mass model with specific mixing angles that can explain recent T2K results indicating a large reactor angle, using deviations from tri-bimaximal mixing within an S4 flavor symmetry framework.

Contribution

It proposes a neutrino mass matrix structure that achieves large reactor angle with maximal atmospheric and trimaximal solar angles, extending beyond traditional tri-bimaximal models.

Findings

Large reactor angle compatible with T2K data

Neutrino mass matrix derived from S4 symmetry

Maintains maximal atmospheric and trimaximal solar angles

Abstract

Recently T2K gives hint in favor of large reactor angle. Most of the models, with tri-bimaximal mixing at the leading order, can not reproduce such a large mixing angle since they predict typically corrections for the reactor angle of the order of the Cabibbo angle. In this letter, we discuss the possibility to have large reactor angle within the T2K region with maximal atmospheric mixing angle and trimaximal solar mixing angle, through the deviation from tri-bimaximal. We derive the structure of neutrino mass matrix that leads to the large reactor angle leaving maximal atmospheric angle and trimaximal solar angle. It is shown that such a structure of neutrino mass matrix can arise in a model with S4 flavor symmetry.