Leptogenesis in Higgs triplet model

We analyze leptogenesis in a supersymmetric triplet seesaw scenario that explains at the same time the baryon asymmetry in the Universe and the observed neutrino masses. First we adopt a phenomenological approach where, in order to single out the main features of the model, the decay branching ratios of the triplets and the amount of CP-violation in their different decay channels are assumed as free parameters. We then consider the particular example of soft leptogenesis, which employs a non-vanishing phase and a resonant behavior in the supersymmetry breaking sector to generate CP violation. In both scenarios we solve the relevant Boltzman equations and show that gauge annihilation processes may strongly suppress the resulting lepton asymmetry. In particular we find that soft leptogenesis is successful only for a triplet mass at the TeV scale, opening up an interesting opportunity for testing the model in future colliders.