Di-Higgs Blind Spots in Gravitational Wave Signals

TL;DR

This paper explores how certain scalar extensions of the Standard Model can produce gravitational wave signals detectable by future experiments like LISA, while simultaneously suppressing di-Higgs signals at colliders, creating blind spots.

Contribution

It identifies conditions under which gravitational wave signals and collider di-Higgs signals are mutually exclusive in a minimal scalar extension of the Standard Model.

Findings

GW signals can be generated with suppressed di-Higgs rates.

Di-boson channels can complement GW and collider searches.

Blind spot configurations depend on scalar mixing angles and masses.

Abstract

Conditions for strong first-order phase transition and generation of observable gravitational wave (GW) signals are very restrictive to the profile of the Higgs potential. Working in the minimal extension of the SM with a new gauge singlet real scalar, we show that the production of signals relevant for future GW experiments, such as LISA, can favor depleted resonant and non-resonant di-Higgs rates at colliders for phenomenologically relevant regimes of scalar mixing angles and masses for the heavy scalar. We perform a comprehensive study on the emergence of these di-Higgs blind spot configurations in GWs and also show that di-boson channels, $ZZ$ and $WW$, can restore the phenomenological complementarities between GW and collider experiments in these parameter space regimes.