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v3.3.2-pre
14:00 Yuber F. Perez-Gonzalez (Northwestern University)
Title: Synergy versus Depletion: the effect of primordial black hole evaporation in leptogenesis
Abstract: Hawking radiation offers a unique method of neutrino production, unlike any weak interaction process. In fact, black hole evaporation depends on whether neutrinos are Dirac or Majorana, providing a different phenomenology in each case. If neutrinos are Majorana, heavy right-handed states like those appearing in the seesaw mechanism can be produced by a black hole, thus modifying the production of lepton asymmetry. In this talk, we will explore the non-trivial interplay between the black hole induced and thermal leptogenesis, demonstrating that for right-handed neutrino masses M > 10^9 GeV there can be an enhancement of the asymmetry. For smaller masses, black holes in fact deplete the baryon-to-photon ratio because of the reheating induced by the evaporation process.
14:30 William Andrew DeRocco (Stanford University)
Title: Muons in supernovae: implications for the axion-muon coupling
Abstract: The high temperature and electron degeneracy attained during a supernova allow for the formation of a large muon abundance within the core of the resulting proto-neutron star. If new pseudoscalar degrees of freedom have large couplings to the muon, they can be produced by this muon abundance and contribute to the cooling of the star. By generating the largest collection of supernova simulations with muons to date, we show that observations of the cooling rate of SN 1987A place strong constraints on the coupling of axion-like particles to muons.