Flavour issues in leptogenesis

Abstract

We study the impact of flavour in thermal leptogenesis, including the quantum\noscillations of the asymmetries in lepton flavour space. In the Boltzmann\nequations we find different numerical factors and additional terms which can\naffect the results significantly. The upper bound on the CP asymmetry in a\nspecific flavour is weaker than the bound on the sum. This suggests that --\nwhen flavour dynamics is included -- there is no model-independent limit on the\nlight neutrino mass scale,and that the lower bound on the reheat temperature is\nrelaxed by a factor ~ (3 - 10).\n