[SEMINARI] SEMINAR: Sacha Davidson, Flavour Matters in Leptogenesis

[German Rodrigo Garcia]

Flavour Matters in Leptogenesis

Sacha Davidson
CNRS/Université Lyon 1
Friday, 9 of February of 2007     12:00 PM
IFIC's Seminar

Abstract

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.