Cogeneration of Dark Matter and Baryons by Non-Standard-Model Sphalerons in Unified Models

Abstract

Sphalerons of a new gauge interaction can convert a primordial asymmetry in B or L into a dark matter asymmetry. From the equilibrium conditions for the sphalerons of both the electroweak and the new interactions, one can compute the ratios of B, L, and X, where X is the dark matter number, thus determining the mass of the dark matter particle fairly precisely. Such a scenario can arise naturally in the context of unification with larger groups. An illustrative model embeddable in $SU(6)\times SU(2)\subset E_6$ is described as well as an equally simple model based on SU(7).

Comments: 13 pages. Revised introduction and references, changed title