PUB - Publikationen an der Universität Bielefeld

We investigate the generation of the baryon asymmetry in two extensions of the Standard Model; these are the SM with a low cut-off and the two-Higgs-doublet model. Analyzing the thermal potential in the presence of CP violation, we find a strong first order phase transition for a wide range of parameters in both models. We compute the relevant bubble wall properties which then enter the transport equations. In non-supersymmetric models electroweak baryogenesis is dominated by top transport, which we treat in the WKB approximation. We calculate the CP-violating source terms starting from the Dirac equation. We show how to resolve discrepancies between this treatment and the computation in the Schwinger-Keldysh formalism. Furthermore, we keep inelastic scatterings of quarks and W bosons at a finite rate, which considerably affects the amount of the generated baryon asymmetry depending on the bubble wall velocity. In addition, we improve the transport equations by novel source terms which are generated by CP-conserving perturbations in the plasma. It turns out that their effect is relatively small. Both models under consideration predict a baryon to entropy ratio close to the observed value for a large part of the parameter space without being in conflict with constraints on electric dipole moments.