Simulations of Cold Electroweak Baryogenesis: Dependence on the source of CP-violation

TL;DR

This study investigates how different sources of CP-violation affect baryon asymmetry generation during a tachyonic electroweak transition, demonstrating that baryogenesis is a robust outcome across various CP-violating terms.

Contribution

It compares four distinct dimension-six CP-violating terms involving the Higgs and scalar fields, showing their effectiveness in producing observed baryon asymmetry.

Findings

All CP-violating terms can generate sufficient baryon asymmetry.

Baryogenesis occurs as a generic outcome of rapid tachyonic electroweak transitions.

Different CP-violation sources lead to similar baryon asymmetry results.

Abstract

We compute the baryon asymmetry created in a tachyonic electroweak symmetry breaking transition, focusing on the dependence on the source of effective CP-violation. Earlier simulations of Cold Electroweak Baryogenesis have almost exclusively considered a very specific CP-violating term explicitly biasing Chern-Simons number. We compare four different dimension six, scalar-gauge CP-violating terms, involving both the Higgs field and another dynamical scalar coupled to SU(2) or U(1) gauge fields. We find that for sensible values of parameters, all implementations can generate a baryon asymmetry consistent with observations, showing that baryogenesis is a generic outcome of a fast tachyonic electroweak transition.