Gluon-induced QCD corrections to pp --> ZZ --> l anti-l l' anti-l'

TL;DR

This paper calculates gluon-induced QCD corrections to the pp --> ZZ --> l anti-l l' anti-l' process, highlighting its significance as a background in Higgs searches at the LHC and quantifying its impact on cross-section predictions.

Contribution

It provides the first detailed calculation of the loop-induced gluon-fusion contribution to ZZ production, emphasizing its importance for Higgs analyses.

Findings

Photon contribution is significant below Z-pair threshold.

Gluon-induced process increases NLO QCD predictions by about 15%.

Results depend on lepton mass cuts.

Abstract

A calculation of the loop-induced gluon-fusion process gg --> Z(photon)Z(photon) --> l anti-l l' anti-l' is presented, which provides an important background for Higgs boson searches in the H --> ZZ channel at the LHC. We find that the photon contribution is important for Higgs masses below the Z-pair threshold and that the gg-induced process yields a correction of about 15% relative to the NLO QCD prediction for the q anti-q-induced process when only a M(l anti-l), M(l' anti-l') > 5 GeV cut is applied.