Orateur
Mario Reig
(CERN)
Description
The topological nature of axion couplings to gauge bosons offers unique opportunities to obtain information about the UV limit of the SM. The coupling to photons is particularly important experimentally. I will discuss why the discovery of an axion-like particle above the QCD line would rule out grand unified theories, the perturbative heterotic string, and F-theory GUTs. Based on 2206.07053, 2410.03820 and 2509.08042.