# QCD axion from chiral gauge theories

## TL;DR

This paper develops supersymmetric chiral gauge theory models that generate QCD axions through non-perturbative dynamics, achieving calculability and compatibility with grand unification.

## Contribution

It introduces new supersymmetric chiral gauge theory models for axions, with calculable IR dynamics and a compatible GUT framework.

## Key findings

- PQ symmetry broken by chiral gauge dynamics
- GUT and PQ scales coincide at high precision
- SUSY breaking scale around 10^9 GeV

## Abstract

We present models of axion based on supersymmetric chiral gauge theories. In these models, the PQ symmetry is spontaneously broken by the non-perturbative dynamics of chiral gauge theory. Thanks to supersymmetry, IR dynamics of the models are calculable. We also present an example of a QCD axion model that is compatible with SU(5) grand unification. We find that in order to realize the gauge coupling unification with a certain precision, the GUT scale is the same with the PQ breaking scale, and the SUSY breaking scale is ${\cal O} (10^9)~{\rm GeV} $.