Gravitational wave and collider implications of electroweak baryogenesis aided by non-standard cosmology

TL;DR

This paper explores how electroweak baryogenesis models can be tested through future collider experiments and gravitational wave observations, especially considering non-standard cosmological histories that expand viable parameter space.

Contribution

It analyzes the detectability of electroweak baryogenesis models via colliders and gravitational waves, highlighting the impact of non-standard cosmology on these prospects.

Findings

Next-generation colliders can confirm or falsify many EWBG models.

Collider searches are generally more powerful than gravitational wave observations.

Modified cosmological histories can enable EWBG with weaker signals, affecting detection strategies.

Abstract

We consider various models realizing baryogenesis during the electroweak phase transition (EWBG). Our focus is their possible detection in future collider experiments and possible observation of gravitational waves emitted during the phase transition. We also discuss the possibility of a non-standard cosmological history which can facilitate EWBG. We show how acceptable parameter space can be extended due to such a modification and conclude that next generation precision experiments such as the ILC will be able to confirm or falsify many models realizing EWBG. We also show that, in general, collider searches are a more powerful probe than gravitational wave searches. However, observation of a deviation from the SM without any hints of gravitational waves can point to models with modified cosmological history that generically enable EWBG with weaker phase transition and thus, smaller GW signals.