# Natural quark mixing and inverse seesaw in a left-right model with an axion

## TL;DR

This paper presents a minimal left-right model with Peccei-Quinn symmetry that addresses strong CP, dark matter, and neutrino mass problems, while providing testable predictions for rare processes.

## Contribution

It introduces a novel minimal scalar sector with Peccei-Quinn symmetry in a left-right framework, linking axion physics with neutrino masses and flavor mixing.

## Key findings

- Addresses strong CP and dark matter problems simultaneously.
- Provides a natural inverse seesaw mechanism for small neutrino masses.
- Predicts potentially observable contributions to neutrinoless double beta decay and lepton flavor violation.

## Abstract

We consider a minimal left-right model with a Peccei-Quinn symmetry, where generalised charge conjugation plays the role of the left-right symmetry. We show how the spontaneous breaking of the Peccei-Quinn symmetry by a scalar singlet can provide us with solutions not only to the strong CP and dark matter problems but can also help to generate naturally suppressed off-diagonal CKM elements and small neutrino masses via the inverse seesaw mechanism. For this, we make use of an economical scalar sector composed of a bi-doublet, two doublets and a singlet only. As a result of the new gauge bosons and neutrinos, the neutrinoless double beta decay, as well as lepton flavour violating processes, receives new contributions which can, in principle, become relevant due to the low-scale nature of the inverse seesaw mechanism. The model can easily accommodate all the current data on fermion masses and mixing even if the left-right scale is only high enough to evade the current experimental constraints.