Cold Electroweak Baryogenesis in the Two Higgs-Doublet Model

TL;DR

This paper investigates cold electroweak baryogenesis within the two Higgs-doublet model, using real-time lattice simulations to identify conditions for baryon asymmetry generation during a spinodal transition.

Contribution

First study of cold electroweak baryogenesis in 2HDM with real-time lattice simulations to determine necessary CP-violating term coefficients.

Findings

Identified the coefficient of the C- and P-breaking term needed for baryogenesis.

Simulated the electroweak transition dynamics in 2HDM.

Demonstrated the feasibility of baryon asymmetry generation in this framework.

Abstract

We perform the first investigation of cold electroweak baryogenesis in the two Higgs-doublet model (2HDM). The electroweak symmetry breaking transition is assumed to occur through a spinodal instability from a super-cooled initial state. We consider the creation of net Chern-Simons number, which through the axial anomaly is equivalent to baryon number. CP-violation is explicit in the scalar potential, but only in combination with P-violation is it possible for an asymmetry to be generated. This is introduced through the leading C- and P-breaking, but CP-invariant, term expected to arise upon integrating out the fermions in the theory. We perform real-time lattice simulations of the transition, and find the coefficient of this term required for successful bayogenesis.