Measuring the Higgs Self-Coupling Constant at a Multi-TeV Muon Collider

TL;DR

This study evaluates the potential of a multi-TeV muon collider to measure the Higgs self-coupling constant, highlighting the impact of collider parameters and detector design on measurement precision.

Contribution

It provides a generator-level analysis of how collider energy spread, cone size, and resolution affect Higgs self-coupling measurement at muon colliders compared to electron colliders.

Findings

Higher energy range improves cross section measurement.

Energy spread reduction enhances measurement precision.

Large cone size due to background complicates detection.

Abstract

A lepton collider in the multi-TeV range has the potential to measure the trilinear Higgs self-coupling constant $\lambda_{hhh}$ via the W-fusion mode $\ell^+\ell^- \rightarrow \nu_\ell \bar{\nu}_\ell h h$. In this paper we do a generator-level study to explore how center-of-mass energy spread, cone size, tracking resolution, and collision energy range affect how precisely a muon collider can measure $\lambda_{hhh}$ in comparison to an $e^+e^-$ collider. The smaller spread in center-of-mass energy and higher energy range of a muon collider improve cross section while the larger cone required to reduce beam-induced background hinders detection of double-Higgs events. Our results motivate a more detailed study of a multi-TeV muon collider and innovative detector and analysis technologies required for background rejection and precision measurement.