Higher-order QCD effects in the Higgs to ZZ search channel at the LHC

TL;DR

This paper analyzes higher-order QCD effects in the Higgs to ZZ search at the LHC, demonstrating the importance of soft-gluon resummation and proposing angular variables for CP property investigation.

Contribution

It provides a consistent analysis of signal and background with soft-gluon resummation and introduces a new angular variable for CP characterization of the Higgs.

Findings

Soft-gluon effects modest but significant for precision.

Transverse momentum cuts enhance signal-to-background ratio.

New angular variable can probe Higgs CP properties.

Abstract

We present a consistent analysis of the signal as well as the irreducible background for the search of the SM Higgs boson in the ZZ decay channel at the LHC. Soft-gluons effects are resummed up to next-to-leading logarithmic accuracy, and the results are compared to those obtained with fixed order calculations and the MC@NLO event generator. The soft-gluon effects are typically modest but should be taken into account when precise predictions are demanded. Our results show that the signal over background ratio can be significantly enhanced with a cut on the transverse momentum pt(ZZ) of the ZZ pair. We also introduce a fully transverse angular variable that could give information about the CP nature of the Higgs boson.