Baryons and Dark Matter from the Late Decay of a Supersymmetric Condensate

The possibility that both the baryon asymmetry and dark matter arise from the late decay of a population of supersymmetric particles is considered. If the decay takes -pl=e below the LSP freeze out temperature, a nonthermal distribution of LSPS results. With conserved R parity these relic LSPS contribute to the dark matter density. A net asymmetry can exist in the population of decaying particles if it arises from coherent production along a supersymmetric flat direction. The asymmetry is transferred to baryons if the condensate decays through the lowest order nonrenormalizable operators which couple to R odd combinations of standard model particles. This also ensures at least one LSP per decay. The relic baryon n and LSP number densities are then roughly equal. The ratio of baryon to dark matter densities is then naturally ~~/~LSP w ~(m~/mLsp). The resulting upper limit on the LSP-mass is model dependent but in the range 0(30 – 140) GeV. The total relic density is related to the order at which the flat direction which gives rise to the condensate is lifted. The observed density is obtained for a direction which is lifted by a fourth order Planck scale suppressed operator in the superpotential. Submitted to Physjcs Letters B