Electroweak Resonant Leptogenesis in the Singlet Majoron Model

Abstract

We study resonant leptogenesis at the electroweak phase transition in the singlet Majoron model with right-handed neutrinos. We consider a scenario, where the SM gauge group and the lepton number break down spontaneously during a second-order electroweak phase transition. We calculate the flavour- and temperature-dependent leptonic asymmetries, by including the novel contributions from the transverse polarisations of the W+/- and Z bosons. The required resummation of the gauge-dependent off-shell heavy-neutrino self-energies is consistently treated within the gauge-invariant framework of the Pinch Technique. Taking into consideration the freeze-out dynamics of sphalerons, we delineate the parameter space of the model that is compatible with successful electroweak resonant leptogenesis. The phenomenological and astrophysical implications of the model are discussed.