CP violation in neutrino mixing matrix and leptogenesis

Abstract

The CP violation required in leptogenesis may have different origin, but in an effective theory they all are related to the rephasing invariant CP violating measure in the mixing matrix of the leptonic sector. We point out that the maximum amount of CP violation in some models can be estimated with our present knowledge of the neutrino mixing angles, which can help us understand the CP violation in the generation of the lepton asymmetry of the universe. For example, the possibility of leptogenesis may be ruled out in some models from an knowledge of the effective neutrino mass matrix.