Particle Theory Seminar: Strong CP and Flavor. - Claudio Manzari, Berkeley

I will discuss a class of multi-Higgs doublet extensions of the Standard Model that solves the strong CP problem with profound consequences for the flavor sector. A flavor symmetry, G, that acts on Higgs and quark fields is a key feature of these theories. CP and G are only softly broken in the scalar potential, so that for certain choices of G charges, the strong CP parameter is zero at tree-level. I will then discuss radiative corrections in this class of theories, as well as the contribution from higher-dimension operators and show that they can both be sufficiently small. Finally, I will discuss the case of spontaneous CP breaking.