%0 Journal Article %T Leptogenesis and dark matter unified in a non-SUSY model for neutrino masses %A Suematsu %A Daijiro %J High Energy Physics - Phenomenology %D 2007 %I %R 10.1140/epjc/s10052-008-0661-z %X We propose a unified explanation for the origin of dark matter and baryon number asymmetry on the basis of a non-supersymmetric model for neutrino masses. Neutrino masses are generated in two distinct ways, that is, a tree-level seesaw mechanism with a single right-handed neutrino, and one-loop radiative effects by a new additional doublet scalar. A spontaneously broken U(1)$^\prime$ brings a $Z_2$ symmetry which restricts couplings of this new scalar and controls the neutrino masses. It also guarantees the stability of a CDM candidate. We examine two possible candidate for the CDM. We also show that the decay of a heavy right-handed neutrino related to the seesaw mechanism can generate baryon number asymmetry through leptogenesis. %U http://arxiv.org/abs/0706.2401