The axion-photon coupling and grand unified theories
Abstract: Being topological quantities, the axion couplings to gauge bosons contain important information about the UV. Among them, the axion-photon coupling is of particular interest experimentally. In this talk I show how in Grand Unified Theories, and in the massless axion limit, only the QCD axion couples to photons. More generally - and due to kinetic or mass mixing - additional, light axion-like particles can appear but with an enormously suppressed coupling to photons.
Zoom link: IPPP Seminars (Thursday at 2 pm UK time)
Meeting ID: 994 2012 4988