Non-invertible Peccei-Quinn symmetry, natural 2HDM alignment, and the visible axion

Abstract

Abstract We identify m 12 2 $$ {m}_{12}^2 $$ as a spurion of non-invertible Peccei-Quinn symmetry in the type II 2HDM with gauged quark flavor. Thus a UV theory which introduces quark color-flavor monopoles can naturally realize alignment without decoupling and can furthermore revive the Weinberg-Wilczek axion. As an example we consider the SU(9) theory of color-flavor unification, which needs no new fermions. This is the first model-building use of non-invertible symmetry to find a Dirac natural explanation for a small relevant parameter.

Keywords

• Multi-Higgs Models
• Axions and ALPs
• Grand Unification
• Theories of Flavour