ZZ production in gluon fusion at NLO matched to parton-shower

TL;DR

This paper calculates NLO QCD corrections to gluon fusion ZZ production, matched with parton shower simulations, providing realistic predictions for the 13 TeV LHC, including interference effects and experimental cuts.

Contribution

It introduces a matched NLO calculation for gg→ZZ in the POWHEG framework, including interference effects and realistic LHC predictions.

Findings

Accurate NLO predictions for gg→ZZ at LHC energies.

Inclusion of interference effects and realistic cuts.

Predictions suitable for experimental analysis.

Abstract

We present a calculation of the next-to-leading order (NLO) QCD corrections to the hadroproduction process $gg\to ZZ \to e^+e^- \mu^+ \mu^-$, matched to the parton shower in the POWHEG framework. We take advantage of the POWHEG BOX tool for the implementation and rely on PYTHIA 8 for the showering and hadronization stages. We fully include $\gamma^*/Z$ interference effects, while also covering the single-resonant region. For this phenomenological study we focus on four lepton production as a signal process, neglecting all quark mass effects as well as the Higgs-mediated contributions, which are known to be subdominant in this case. We provide predictions from our simulations for the 13 TeV LHC Run II setup, including realistic experimental cuts.