I study variations of the standard leptogenesis scenario that can arise if an additional mass scale related to the breaking of some new symmetry is present below the mass $M_{ N_1}$ of the lightest right-handed Majorana neutrino. I present a particular realization of this scheme that allows for leptogenesis at the TeV scale. In this realization the baryon asymmetry is exclusively due to flavor effects.
Categories: hep-ph