Leptogenesis without on-shell right-handed neutrinos
This paper proposes leptogenesis without needing heavy right-handed neutrinos to be produced on-shell. It introduces a lighter scalar field that decays into leptons and Higgs doublets via off-shell right-handed neutrinos, generating a lepton asymmetry through CP violation. This mechanism successfully produces the baryon asymmetry of the Universe while avoiding constraints imposed by having heavy neutrinos in the primeval plasma.