Electroweak phase transition in SMEFT: Gravitational wave and collider complementarity

TL;DR

This paper explores how dimension-6 operators in SMEFT can induce a first-order electroweak phase transition, and how gravitational wave detection and collider experiments can jointly probe these phenomena.

Contribution

It analyzes the complementarity of gravitational wave signals and collider searches in probing SMEFT operators related to electroweak phase transition.

Findings

High-luminosity LHC can improve sensitivity to di-Higgs production.

Gravitational wave observations can complement collider searches.

Correlations among SMEFT operators are crucial for probing phase transition.

Abstract

We study the electroweak first-order electroweak phase transition (FO-EWPT) within the Standard Model Effective Field Theory (SMEFT) framework induced by dimension-6 operators. Such phenomena can be probed independently via \textit{di}-Higgs production at the collider experiments as well as via the detection of gravitational waves (GW). There are three dimension-6 SMEFT operators that simultaneously modify the Higgs potential at tree level and contribute to the \textit{di}-Higgs production at the hadron colliders. With \textit{di}-Higgs production being suppressed at current LHC runs, we aim to probe this production at high luminosity (HL) and high energy (HE) runs of the LHC to achieve better sensitivity of dimension-6 SMEFT operators. The correlations among these operators are analyzed in the context of probing FO-EWPT, emphasizing the complementarity between future GW observations and upgraded LHC searches.