The flavor problem and discrete symmetries

TL;DR

This paper proposes a multi-Higgs extension of the Standard Model incorporating discrete symmetries, resulting in diagonal charged fermion mass matrices and neutrino masses generated mainly by higher-dimensional operators.

Contribution

It introduces a novel multi-Higgs model with discrete symmetries that naturally produce diagonal charged fermion matrices and neutrino masses from non-renormalizable interactions.

Findings

Charged fermion mass matrices are diagonal at renormalizable level.

Neutrino masses originate from dimension five and six operators.

Deviations from diagonality are induced by non-renormalizable interactions.

Abstract

In this letter we propose a multi-Higgs extension of the standard model with Abelian and non-Abelian discrete symmetries in which the mass matrices of the charged fermions obtained from renormalizable interactions are diagonal. Corrections induced by non-renormalizable interactions deviate these matrices from the diagonal form. Active neutrinos acquire mass only from non-renormalizable interactions. The main entries of the neutrino mass matrix arise only through dimension five operators, while the diagonal entries arise only from dimension six operators.