On the connection of leptogenesis with low energy CP violation and lepton flavor violating charged lepton decays

The biunitary parametrization of the neutrino Dirac mass matrix m(D) of the seesaw mechanism of neutrino mass generation is considered in detail. Assuming a hierarchical structure of m(D) and of the heavy Majorana neutrino masses M-1,M-2,M-3>0, M-110(3)M(1)), we find that, in order to produce the observed baryon asymmetry of the Universe via leptogenesis, the scale of m(D) should be given by the up-quark masses, m(D)similar tom(up). It is also possible to reproduce the low-energy neutrino mixing phenomenology for m(D)similar tom(up) if one of the heavy Majorana neutrinos is much heavier than the other two and there exists only a rather mild hierarchy between the masses of the latter (M(2)congruent to10 M-1). In the case of a strong hierarchy between M-3 and M-1,M-2, successful leptogenesis requires a mild hierarchy between M-1 and M-2 as well. In this scenario, the effective Majorana mass in neutrinoless double beta decay depends on the CP violating phase controlling the leptogenesis if m(D1) is negligible. The lepton flavor violating decays mu-->e+gamma, tau-->mu+gamma and tau-->e+gamma are considered and a characteristic relation between their decay rates is predicted. The CP violation effects in neutrino oscillations can be observable. In general, there is no direct connection between the latter and CP violation in leptogenesis. If the CP violating phases of the seesaw model satisfy certain relations, the baryon asymmetry of the Universe and the rephasing invariant J(CP) which determines the magnitude of the CP violation effects in neutrino oscillations depend on the same CP violating phase and their signs are correlated.