Measurement of $\mathrm{H} \to \mu^+ \mu^-$ production in association with a Z boson at the CEPC

TL;DR

This paper assesses the CEPC's potential to precisely measure the Higgs boson decay into muons in association with a Z boson, demonstrating high significance and accurate coupling measurement capabilities.

Contribution

It provides a simulation-based feasibility study of measuring the Higgs to muon decay at CEPC, including detector effects and decay channel analysis.

Findings

Signal significance over 10 standard deviations

Higgs-muon coupling measurable within 10% accuracy

Feasibility of Higgs property studies at CEPC confirmed

Abstract

The Circular Electron-Positron Collider (CEPC) is a future Higgs factory proposed by the Chinese high energy physics community. It will operate at a center-of-mass energy of 240-250 GeV and is expected to accumulate an integrated luminosity of 5 ab$^{\rm{-1}}$ with ten years of operation. At CEPC, Higgs bosons are dominantly produced from $ZH$ associated process. Vast amount of Higgs events collected will enable precise studies of its properties including Yukawa couplings to massive particles. With {\sc GEANT4}-based simulation of detector effects, we study CEPC feasibility on measuring Higgs boson decaying into a pair of muons. The results with or without information from Z boson decay products are provided, which show a signal significance of over 10 standard deviations can be achieved and the H-$\mathrm{\mu}$-$\mathrm{\mu}$ coupling can be measured within $10\%$ accuracy.