# Gravitational wave and collider probes of a triplet Higgs sector with a low cutoff

## TL;DR

This paper investigates a scalar triplet extension of the Standard Model with a low cutoff, focusing on gravitational wave signals from electroweak phase transitions and collider signatures, offering new ways to probe the model.

## Contribution

It analyzes the gravitational wave signals and collider phenomenology of a low-cutoff scalar triplet model, highlighting unique signatures and experimental prospects.

## Key findings

- LISA can probe the parameter space with strong first-order phase transitions.
- Collider searches, including pair-production of charged scalars, can test the model.
- The model's collider signatures differ significantly from the renormalizable case.

## Abstract

We study the scalar triplet extension of the standard model with a low cutoff, preventing large corrections to the quadratic masses that would otherwise worsen the hierarchy problem. We explore the reach of LISA to test the parameter space region of the scalar potential (not yet excluded by Higgs to diphoton measurements) in which the electroweak phase transition is strongly first-order and produces sizeable gravitational waves. We also demonstrate that the collider phenomenology of the model is drastically different from its renormalizable counterpart. We study the reach of the LHC in ongoing searches and project bounds for the HL-LHC. Likewise, we develop a dedicated analysis to test the key but still unexplored signature of pair-production of charged scalars decaying to third-generation quarks: $pp\rightarrow t\overline{b} (\overline{t}b), b\overline{b}$. These results apply straightforwardly to other extensions of the Higgs sector such as the 2HDM/MSSM.