Automatic Peccei-Quinn symmetry

TL;DR

This paper introduces a dynamical axion model where the Peccei-Quinn symmetry naturally emerges from gauge and chiral symmetries, extending the Standard Model with a new confining gauge sector.

Contribution

It proposes a novel composite axion model with an automatic PQ symmetry arising from gauge and chirality, protected from quantum gravity effects.

Findings

Peccei-Quinn symmetry arises automatically from gauge and chiral symmetries.

The model extends the Standard Model with a confining $SU(5)$ gauge sector.

The PQ symmetry aligns with a $B-L$ symmetry of the exotic sector.

Abstract

We present a dynamical (composite) axion model where the Peccei-Quinn (PQ) symmetry arises automatically as a consequence of chirality and gauge symmetry. The Standard Model is simply extended by a confining and chiral $SU(5)$ gauge symmetry. The PQ symmetry coincides with a $B-L$ symmetry of the exotic sector. The theory is protected by construction from quantum gravitational corrections stemming from operators with mass dimension lower than nine.