Right-handed sector leptogenesis

Abstract

Instead of creating the observed baryon asymmetry of the universe by the decay ofright-handed (RH) neutrinos to left-handed leptons, we propose to generate it dominantlyby the decay of the RH neutrinos to RH leptons. This mechanism turns out to be successfulin large regions of parameter space. It may work, in particular, at a scale as lowas ∼TeV, with no need to invoke quasi-degenerate RH neutrino masses to resonantly enhance theasymmetry. Such a possibility can be probed experimentally by the observation at collidersof a singlet charged Higgs particle and of RH neutrinos. Other mechanisms which may leadto successful leptogenesis from the RH lepton sector interactions are also briefly presented.The incorporation of these scenarios in left–right symmetric and unified models isdiscussed.