Speaker
Description
Dirac Leptogenesis is a viable scenario that connects the observed baryon asymmetry of our universe to the possibility that neutrinos are Dirac fermions. After reviewing the basic ingredients of this approach we present two models for parametrically small Dirac neutrino masses. Both constructions also allow for the generation of a lepton asymmetry from out-of-equilibrium particle decays, that gets reprocessed into a baryon asymmetry via the electroweak sphaleron process. The first model relies on a scalar decaying during reheating and requires a strong resonant enhancement to produce enough CP violation. Our second model with decaying fermions offers a novel non-resonant enhancement of the required CP violation together with a way to make the asymmetry generation more efficient, that was previously only known for Majorana scenarios.