Scalar Dark Matter, GUT baryogenesis and Radiative neutrino mass

Abstract

We investigate an interesting correlation among dark matter phenomenology, neutrino mass generation and GUT baryogenesis, based on the scotogenic model. The model contains additional right-handed neutrinos $N$ and a second Higgs doublet $Φ$, both of which are odd under an imposed $Z_2$ symmetry. The neutral component of $Φ$, i.e. the lightest of the $Z_2$-odd particles, is the dark matter candidate. Due to a Yukawa coupling involving $Φ$, $N$ and the Standard Model leptons, the lepton asymmetry is converted into the dark matter asymmetry so that a non-vanishing $B-L$ asymmetry can arise from $(B-L)$-conserving GUT baryogenesis, leading to a nonzero baryon asymmetry after the sphalerons decouple. On the other hand, $Φ$ can also generate neutrino masses radiatively. In other words, the existence of $Φ$ as the dark matter candidate resuscitates GUT baryogenesis and realizes neutrino masses.