Affleck-Dine Cogenesis

Abstract

We propose a novel framework in which the observed baryon and dark matter abundances are simultaneously generated via the Affleck-Dine mechanism. In its simplest realization, Affleck-Dine cogenesis is accomplished by a single superpotential operator and its A-term counterpart. These operators explicitly break B-L and X, the dark matter number, to the diagonal B-L+X. In the early universe these operators stabilize supersymmetric flat directions carrying non-zero B-L and X, and impart the requisite CP violation for asymmetry generation. Because B-L+X is preserved, the resulting B-L and X asymmetries are equal and opposite, though this precise relation may be relaxed if B-L and X are violated separately by additional operators. Our dark matter candidate is stabilized by R-parity and acquires an asymmetric abundance due to its non-zero X number. For a dark matter mass of order a few GeV, one naturally obtains the observed ratio of energy densities today, Omega_{DM}/Omega_B \sim 5. These theories typically predict macroscopic lifetimes for the lightest observable supersymmetric particle as it decays to the dark matter.

Comments: 9 pages, no figures. References and minor changes in v2 to reflect published version