Radiative Return for Heavy Higgs Boson at a Muon Collider

TL;DR

This paper explores the potential of a muon collider to discover and study heavy Higgs bosons using radiative return and other production mechanisms, even when operating off the resonance energy.

Contribution

It introduces the radiative return process as a viable method for heavy Higgs detection at muon colliders, comparing it with other production channels across various Two Higgs Doublet Models.

Findings

Radiative return can effectively discover heavy Higgs bosons.

The method allows measurement of invisible Higgs decays.

It is less dependent on prior mass knowledge.

Abstract

Higgs boson properties could be studied with a high accuracy at a muon collider via the s-channel resonant production. We consider the situation where the center-of-mass energy of the muon collider is off the resonance above the Higgs mass. We discuss the discovery potential for a generic heavy Higgs boson ($H$) and compare different production mechanisms, including the "radiative return" ($\gamma H$), $Z$-boson associated production ($ZH$) and heavy Higgs pair production ($HA$). These production mechanisms do not sensitively rely on a priori knowledge of the heavy Higgs boson mass. We include various types of Two Higgs Doublet Models for the comparison. We conclude that the radiative return process could provide an important option for both the heavy Higgs discovery and direct measurement of invisible decays at a high energy muon collider.