CP-Violating Reflection of High Energy Fermions during a first order Phase Transition

Abstract

We study the high energy behaviour of fermions hitting a general wall caused by a first-order phase transition. The wall profile is introduced through general analytic and non-analytic functions. The reflection coefficient is computed in the high energy limit and its connection with the analytic properties of the wall profile function is shown. The high energy behaviour of the fermions hitting the wall is determined either by the leading singularity, i.e. the closest pole to the real axis, when the profile function is analytic, or by the first non-continuous derivative on the real axis, in the non-analytic case. CP-violating wall profiles are studied and it is shown that the respective symmetry properties of the CP-conserving and CP-violating profile functions plays an important role on the size of the CP asymmetry.