Flavoured leptogenesis: a successful thermal leptogenesis with N₁ mass below 10⁸ GeV

We prove that taking correctly into account the lepton flavour dependence of the CP asymmetries and washout processes, it is possible to obtain successful thermal leptogenesis from the decays of the second right-handed neutrino. The asymmetries in the muon and tau-flavour channels are then not erased by the inverse decays of the lightest right-handed neutrino, N_1. In this way, we reopen the possibility of ``thermal leptogenesis'' in models with a strong hierarchy in the right-handed Majorana masses that is typically the case in models with up-quark--neutrino Yukawa unification.