Axion model with the $\mathrm{SU}(6)$ unification

Ning Chen, Yutong Liu, Zhaolong Teng

We propose an $\mathrm{SU}(6)$ unified theory that solves the strong $CP$ problem with a high-quality axion. This is achieved by an automatic global Peccei-Quinn ${\rm U}(1)_{\r…