LABORATORI NAZIONALI DI FRASCATI
Speaker: R. Ziegler (TTP/KIT)
I will discuss a simple QCD axion model that arises from identifying Peccei-Quinn with Froggatt-Nielsen symmetries. The flavor problem of the Standard Model is addressed by a U(1) flavor symmetry, which naturally leads to an axion that solves the strong CP problem. The ratio of the axion mass and its coupling to photons is related to SM fermion masses and predicted within a small range, as a direct result of the observed fermion mass hierarchies. The same hierarchies determine the axion couplings to fermions, making the framework very predictive and experimentally testable by future axion and precision flavor experiments.