Similar Dark Matter and Baryon abundances with TeV-scale Leptogenesis

Abstract: We estimate the Baryon Asymmetry of the Universe (BAU) produced in an inverse seesaw model containing extra light singlets, and with lepton number conservation prior to the electroweak phase transition. An order one CP asymmetry epsilon is required to obtain a large enough BAU. We discuss the relation between the baryon and WIMP relic densities in baryogenesis scenarios using the out-of-equilibrium decay of a baryon-parent of mass M: when baryon number violation freezes out, the remaining density of baryon-parents is of order M/m_W times the WIMP relic density. So the baryon/WIMP ratio is or order epsilon M/m_W. A natural explanation of the similar WIMP and baryon densities could be that CP violation is of order the ratio m_W/M.