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 $Phi$, 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 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, $Phi$ 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.
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