Baryogenesis with scalar bilinears

We show that if the baryon asymmetry of the universe is generated through the out-of-equilibrium decays of heavy scalar bilinears coupling to two fermions of the minimal standard model, it is necessarily an asymmetry conserving (B-L) that cannot survive past the electroweak phase transition because of sphalerons. We then show that a surviving (B-L) asymmetry may be generated if the heavy scalars decay into two fermions, and into two light scalars (which may be detectable at hadron colliders). We list all possible such trilinear scalar interactions, and discuss how our new baryogenesis scenario may occur naturally in supersymmetric grand unified theories.