Generation of baryon inhomogeneities in the electroweak phase transition

Abstract

It is known that baryon number inhomogeneities may arise as a consequence of electroweak baryogenesis. Their geometry, size, and amplitude depend on the parameters that characterize the baryogenesis mechanism, as well as on those that determine the phase transition dynamics. We investigate this parametric dependance. We show that in the case of the minimal supersymmetric standard model, the geometry of the inhomogeneities most probably consists of spherical regions of high density surrounded by low-density walls, in contrast to the case of the minimal standard model. In this supersymmetric extension we find that density contrasts of up to a factor of 100 may arise. This amplitude increases for higher values of the latent heat or lower values of the bubble wall tension, and can be significantly larger in different extensions of the standard model. Such inhomogeneities may thus affect the dynamics of the subsequent quark-hadron phase transition.