Simulations of Domain Walls in Two Higgs Doublet Models

TL;DR

This paper investigates the formation and dynamics of domain walls in Two Higgs Doublet Models through numerical simulations, revealing complex network behaviors and local symmetry violations.

Contribution

It provides the first numerical solutions and dynamical simulations of domain walls in 2HDM, highlighting their network evolution and symmetry-breaking features.

Findings

Domain walls form networks deviating from power law scaling.

Winding of electroweak parameters occurs around domain walls.

Local violation of neutral vacuum condition observed on walls.

Abstract

The Two Higgs Doublet Model predicts the emergence of 3 distinct domain wall solutions arising from the breaking of 3 accidental global symmetries, $Z_2$, CP1 and CP2, at the electroweak scale for specific choices of the model parameters. We present numerical kink solutions to the field equations in all three cases along with dynamical simulations of the models in (2+1) and (3+1) dimensions. For each kink solution we define an associated topological current. In all three cases simulations produce a network of domain walls which deviates from power law scaling in Minkowski and FRW simulations. This deviation is attributed to a winding of the electroweak group parameters around the domain walls in our simulations. We observe a local violation of the neutral vacuum condition on the domain walls in our simulations. This violation is attributed to relative electroweak transformations across the domain walls which is a general feature emerging from random initial conditions.