Physics potential for the H$\rightarrow$ZZ$^{*}$ decay at the CEPC

TL;DR

This paper evaluates the precision of measuring the Higgs boson decay into ZZ* at the CEPC, demonstrating a 7.9% accuracy using advanced analysis techniques, which aids in understanding Higgs properties.

Contribution

It introduces a detailed analysis of the H→ZZ* decay channel at the CEPC, including a comparison of analysis methods and an estimation of measurement precision.

Findings

Estimated measurement precision of 7.9% for σ_ZH·BR(H→ZZ*)

Demonstrated the effectiveness of boosted decision trees in analysis

Projected the Higgs width measurement accuracy using this decay channel

Abstract

The precision of the yield measurement of the Higgs boson decaying into a pair of $Z$ bosons process at the Circular Electron Positron Collider (CEPC) is evaluated. Including the recoil $Z$ boson associated with the Higgs production (Higgsstrahlung) total three $Z$ bosons are involved for this channel, from which final states characterized by the presence of a pair of leptons, quarks, and neutrinos are chosen for the signal. Two analysis approaches are compared and the final precision of ${\sigma}_{\mathrm{ZH}}{\cdot}$BR($H \rightarrow ZZ^{*}$) is estimated to be 7.9% using a multivariate analysis technique, based on boosted decision trees. The relative precision of the Higgs boson width, using this $H \rightarrow ZZ^{*}$ decay topology, is estimated by combining the obtained result with the precision of the inclusive \textit{ZH} cross section measurement.