Speaker
Description
We present an axion model based on the Pati-Salam group, where $\mathrm{SU}(3)_{f_R}$ (part of flavor symmetry) has also been gauged. The choice of field content ensures a careful interplay of the two symmetries, such that an accidental global $\mathrm{U}(1)$ Peccei-Quinn (PQ) symmetry emerges. The resulting axion is of high quality for the breaking scale in a certain range, and the model's Yukawa sector is realistic. A characteristic feature of having both a vertical (Pati-Salam) and horizontal (flavor) symmetry are anomalons --- parametrically light fermions required to cancel gauge anomalies. We analyze their interplay with neutrinos and their production in the early universe. Their effect on $\Delta N_{\text{eff}}$ could serve as a low energy probe for the underlying dynamics of PQ quality.
