Spontaneous R-Parity Violation and Electroweak Baryogenesis

The possibility of baryogenesis at the electroweak phase transition is considered within the context of a minimal supersymmetric standard model with spontaneous R-parity violation. Provided that at least one of the sneutrino fields acquires a large enough vacuum expectation value, a sufficient baryon asymmetry can be created. Compared to R-parity conserving models the choice of soft supersymmetry breaking parameters is less restricted. The observed baryon asymmetry, n_B/s ~ 10^(-10), can be explained by this scenario and the produced baryon-to-entropy ratio may easily be as high as n_B/s ~ 10^(-9).