S4 as a natural flavor symmetry for lepton mixing

TL;DR

This paper demonstrates that the S4 symmetry group can naturally produce tribimaximal neutrino mixing, providing model-independent proofs and two explicit models with different symmetry breaking mechanisms.

Contribution

It proves that S4 can realize exact tribimaximal mixing in a model-independent way and presents two models illustrating different symmetry breaking patterns.

Findings

S4 can produce exact tribimaximal mixing

Two distinct models achieve tribimaximal mixing

Superpotentials for symmetry breaking are explicitly constructed

Abstract

Group theoretical arguments seem to indicate the discrete symmetry S4 as the minimal flavour symmetry compatible with tribimaximal neutrino mixing. We prove in a model independent way that indeed S4 can realize exact tribimaximal mixing through different symmetry breaking patterns. We present two models in which lepton tribimaximal mixing is realized in different ways and for each one we discuss the superpotential that leads to the correct breaking of the flavor symmetry.