Strong electroweak phase transitions without collider traces

TL;DR

This paper explores whether future experiments can detect strong electroweak phase transitions, especially in models that closely resemble the Standard Model at low energies but still allow for observable gravitational waves.

Contribution

It demonstrates that certain singlet extensions of the Standard Model can produce strong electroweak phase transitions without detectable collider signatures.

Findings

Models can have strong phase transitions with minimal collider signals

Potential for gravitational wave detection from such phase transitions

Parameter space exists where low-energy phenomenology remains Standard Model-like

Abstract

We discuss the question if the upcoming generation of collider and low-energy experiments can successfully probe the nature of the electroweak phase transition. In particular, we are interested in phase transitions strong enough for electroweak baryogenesis or even for a production of gravitational radiation observable by the Big Bang Observer. As an explicit example, we present an analysis in a singlet extension of the Standard Model. We focus on the region in parameter space where the model develops no significant deviation in its low energy phenomenology from the Standard Model. Nevertheless, this class of models can develop a very strong phase transition.