Exact accidental U(1) symmetries for the axion

We study a class of gauge groups that can automatically yield a perturbatively exact Peccei-Quinn symmetry, and we outline a model in which the axion quality problem is solved at all operator dimensions. Gauge groups belonging to this class can also enforce and protect accidental symmetries of the clockwork type, and we present a toy model where an invisible axion arises from a single low scale breaking of the gauge and global symmetries.

Automated summary

We studied a class of gauge groups that can provide a perturbatively exact Peccei-Quinn symmetry, and proposed a model in which the axion quality problem is resolved at all operator dimensions. These gauge groups can also enforce and protect accidental symmetries of the clockwork type, as demonstrated in a toy model where an invisible axion results from a low scale breaking of gauge and global symmetries.