CP-Violation and Baryogenesis on Electroweak Scales

Abstract

In this work we study different aspects of CP-violation on electroweak scales and in this context quantum transport in electroweak baryogenesis. First we focus on CP-violation of CKM type as it is present in the Standard Model. We explain basic concepts and the reason for the smallness of CP-violation in direct observations and introduce theoretical bounds on CP-violation in the Standard Model. We discuss the prerequisites of the Jarlskog determinant and give some examples where these assumptions are not satisfied in a cosmological setting. We find that these bounds can be dissatisfied due to space-time dependent masses or non-perturbative effects. One of the examples is linked to effective actions of chiral gauge theories and we present a formalism to determine effective actions based on the worldline representation of path integrals. The main part of the present work deals with transport theory of quantum systems. Based on the derivation of quantum transport equations for one flavour we generalize to mixing systems with several flavours. One prominent and novel feature of our formalism is the appearance of oscillations of the off-diagonal densities analogous to neutrino oscillations. Using our approach in the concrete case of MSSM we find that electroweak baryogenesis is insufficient to explain the observed value of baryon asymmetry generically.