Speaker
Description
Supernova explosions would emit large numbers of axions (and axionlike particles) if these hypothetical particles have masses of at most a few hundred MeV and couplings to nucleons, pions, electrons, muons, or photons. The emitted relativistic axions can lead to directly observable signals through decays or conversions to photons, which would also efficiently happen at the one-loop level. Thus, the potential photon signal does not require tree-level photon couplings. We show how the resulting gamma rays can be observed with gamma-ray detectors such as the Fermi-LAT even for extragalactic supernovae, e.g., the relatively recent SN 2023ixf. We discuss the possibility to infer detailed axion properties in case of a detection. Furthermore, the relativistic axions can be observed directly through rare scattering events in neutrino detectors such as Super-K, Hyper-K, or JUNO. We discuss predictions for event rates and which axion masses and couplings are potentially observable in those detectors.
