Friday, January 29, 2016 - 13:00
Symmetries for low and high energy CP phases
Leptonic low energy CP phases, of Dirac as well as Majorana type, can be predicted with the help of flavour and CP symmetries. However, the high energy CP phases in the lepton sector, relevant for leptogenesis, are in general unrelated to those at low energies and thus represent new sources of CP violation. We discuss a scenario in which all CP phases are constrained by flavour and CP symmetries. In this way, the CP violation at low and high energies becomes intimately related and, in particular, the sign of the baryon asymmetry of the Universe, generated via the mechanism of unflavoured leptogenesis, is fixed.