  The similarity of the observed mass densities of baryons and cold dark matter
may be a sign they have a related origin. The baryon-to-dark matter ratio can
be understood in the MSSM with right-handed (RH) neutrinos if CDM is due to a d
= 4 flat direction condensate of very weakly coupled RH sneutrino LSPs and the
baryon asymmetry is generated by Affleck-Dine leptogenesis along a d = 4
(H_{u}L)^2 flat direction. Observable signatures of the model include CDM and
baryon isocurvature perturbations and distinctive long-lived NLSP
phenomenology.
