Dark matter and the baryon asymmetry of the universe

We present a mechanism to generate the baryon asymmetry of the Universe which preserves the net baryon number created in the big bang. If dark matter particles carry baryon number B-X, and sigma(annih)(X) < sigma(annih)(X), the (X) over bar 's freeze-out at a higher temperature and have a larger relic density than X's. If m(X)less than or similar to 4.5B(X) GeV and the annihilation cross sections differ by O(10%) or more, this type of scenario naturally explains the observed Omega(DM)approximate to 5 Omega(b).