Flavored axions and the flavor problem

TL;DR

This paper introduces a model with flavored axions and a Peccei-Quinn symmetry to explain quark masses and mixing, predicting flavor-changing neutral currents constrained by meson decay data.

Contribution

It proposes a new PQ symmetry-based model with five texture-zero mass matrices requiring four Higgs doublets, offering insights into SM mass scales and flavor physics.

Findings

Identifies allowed parameter space consistent with meson decay measurements.

Demonstrates the necessity of four Higgs doublets for Hermitian mass matrices with texture zeros.

Provides analytical expressions for flavor-changing neutral currents.

Abstract

A Peccei-Quinn~(PQ) symmetry is proposed in order to generate in the Standard Model~(SM) quark sector a realistic mass matrix ansatz with five texture-zeros. Limiting our analysis to Hermitian mass matrices, we show that this requires a minimum of 4 Higgs doublets. This model allows assigning values close to 1 for several Yukawa couplings, giving insight into the origin of the mass scales in the SM. Since the PQ charges are non-universal, the model features Flavor-Changing Neutral Currents~(FCNC) at the tree level. From the analytical expressions for the FCNC we report the allowed region in the parameter space obtained from the measurements of branching ratios of semileptonic meson decays.