Weak boson probes of Higgs unitarity restoration at 10 TeV parton colliders

TL;DR

This paper explores how future high-energy colliders can detect deviations in Higgs couplings that threaten unitarity, estimating their sensitivity to new physics up to around 6 TeV.

Contribution

It provides a comparative analysis of the sensitivity of 10 TeV muon colliders and 100 TeV hadron colliders to Higgs coupling deviations related to unitarity restoration.

Findings

Both collider types can probe mass scales up to approximately 6 TeV.

Higgs coupling deviations at sub-percent levels can indicate unitarity violation.

Intermediate FCC-ee measurements can support collider findings.

Abstract

Higgs coupling deviations, at levels accessible to the high-luminosity LHC, can imply a phenomenological no-lose theorem for the next generation of collider facilities. Correlating Higgs coupling deviations from the SM expectation in the gauge boson sector with high-scale unitarity requirements, we estimate and compare the sensitivity that can be expected at a future hadron collider (operating at 100 TeV centre-of-mass energy) and a 10 TeV muon collider. Both muon and hadron colliders offer discovery potential for mass scales up to ${\cal{O}}(6~\text{TeV})$ where unitarity violation induced by (sub)percent Higgs coupling modifications is mended. We comment on how an intermediate precision FCC-ee programme can corroborate such deviations.