Flavour Matters in Leptogenesis

por Sacha Davidson (CNRS/Université Lyon 1)

viernes 9 feb. 2007 12:00 → 13:00 Europe/Madrid

Sala Seminarios IFIC (Edf. Institutos de Investigación)

Thermal leptogenesis is an attractive mechanism to generate the matter we are made of. In the hot early Universe, a lepton asymmetry is produced by the interactions of a very heavy ( $M \sim 10^9$ GeV) singlet neutrino, and then reprocessed, by non-perturbative Standard Model interactions, into a baryon asymmetry. The dynamics of producing an asymmetry in total lepton number has been carefully studied in the past. I will argue that it is important to follow the evolution of the three (or two) flavoured lepton asymmetries. This generically enhances the predicted baryon asymmetry, because more CP violation is allowed and washout is reduced. The "leptogenesis bound" on the light neutrino mass scale disappears.