Lepton mass and mixing in a simple extension of the Standard Model based on T7 flavor symmetry

TL;DR

This paper proposes a simple extension of the Standard Model using T7 flavor symmetry to explain lepton masses and mixing, successfully incorporating non-zero theta_13 and CP violation with minimal assumptions.

Contribution

It introduces a novel T7 flavor symmetry-based model that naturally produces realistic lepton mixing patterns and predicts a specific Dirac CP violation phase.

Findings

Predicts Dirac CP phase δ_CP=172.598° in both hierarchies

Achieves realistic lepton mixing with a single vacuum expectation value

Provides small neutrino masses through specific SU(2)_L representations

Abstract

A simple Standard Model Extension based on $T_7$ flavor symmetry which accommodates lepton mass and mixing with non-zero $\theta_{13}$ and CP violation phase is proposed. At the tree- level, the realistic lepton mass and mixing pattern is derived through the spontaneous symmetry breaking by just one vacuum expectation value ($v$) which is the same as in the Standard Model. Neutrinos get small masses from one $SU(2)_L$ doublet and two $SU(2)_L$ singlets in which one being in $\underline{1}$ and the two others in $\underline{3}$ and $\underline{3}^*$ under $T_7$ , respectively. The model also gives a remarkable prediction of Dirac CP violation $\delta_{CP}=172.598^\circ$ in both normal and inverted hierarchies which is still missing in the neutrino mixing matrix.