Scalar dark matter, GUT baryogenesis, and radiative neutrino mass

We investigate an interesting correlation among dark matter phenomenology, neutrino mass generation and grand unified theory (GUT) baryogenesis, based on the scotogenic model. The model contains additional right-handed neutrinos N and a second Higgs doublet Phi, both of which are odd under an imposed Z(2) symmetry. The neutral component of Phi, i.e. the lightest of the Z(2)-odd particles, is the dark matter candidate. Due to a Yukawa coupling involving Phi, N and the standard model leptons, the lepton asymmetry is converted into the dark matter asymmetry so that a nonvanishing B - L asymmetry can arise from (B - L)-conserving GUT baryogencsis, leading to a nonzero baryon asymmetry after the sphalcrons decouple. On the other hand, Phi can also generate neutrino masses radiatively. In other words, the existence of Phi as the dark matter candidate resuscitates GUT baryogenesis and realizes neutrino masses.