Inverted mass hierarchy from a flavored axion-neutrino model

TL;DR

This paper presents a minimal flavored axion model combining the KSVZ axion and type-I seesaw mechanisms, predicting an inverted neutrino mass hierarchy and exploring axion-neutrino couplings' effects on neutrino oscillations.

Contribution

It introduces a novel minimal flavored axion model with specific lepton mass textures and predicts an inverted neutrino mass hierarchy, linking axion physics with neutrino phenomenology.

Findings

Predicts an inverted hierarchy of neutrino masses with specific mass ratios.

Identifies a hierarchy between the VEVs of two SM-singlet scalars.

Explores potential effects of axion-neutrino couplings on neutrino oscillations.

Abstract

Combining the KSVZ axion model and the type-I seesaw mechanism, we construct a minimal flavored axion model that can affect the neutrino mass matrix. This minimal model requires a flavor dependent PQ charge assignment and two additional standard model (SM) singlet scalars which generate specific patterns of lepton mass matrices, yielding a particular texture of Majorana neutrino mass matrix. Combined with fact that $\theta _{13}$ is much smaller than the other mixing angles, this texture predicts an Inverted Hierarchy of neutrino masses with $17\lesssim m_1/m_3\lesssim 44$, and a hierarchy between the two VEVs of SM-singlet scalars. We also examine the couplings between the axion and the leptons in this model. Especially, the axion-neutrino couplings have the potential effect on neutrino oscillation.