QCD NLO corrections to $t\bar{t}Z$ production at the LHC including leptonic decays

TL;DR

This paper advances the theoretical modeling of $t\bar{t}Z$ production at the LHC by computing NLO QCD corrections including leptonic decays, improving event simulation accuracy for experimental analyses.

Contribution

It presents the first NLO QCD calculations of fully decayed $t\bar{t}Z$ processes and matches NLO calculations to parton showers with top-quark decay modeling.

Findings

Enhanced accuracy in $t\bar{t}Z$ event simulation.

Improved theoretical predictions for leptonic decay channels.

State-of-the-art NLO QCD calculations for $t\bar{t}Z$ production.

Abstract

The calculation of $t\bar{t}Z$ production including leptonic decays of both $Z$ boson and top quarks via a partially or fully off-shell calculation represents a definite step forward towards a more accurate description of events whose signatures originate from $t\bar{t}Z$ production. In this talk we review two studies that represent the state of the art of theoretical modeling of $t\bar{t}Z$ production by either performing the NLO QCD calculation of the fully decayed $pp\rightarrow e^+\nu_e\mu^-\bar{\nu}_\mu b\bar{b}\tau^+\tau^-$ process (see Ref. [1]) or matching the NLO QCD calculation of $pp\rightarrow t\bar{t}\ell^+\ell^-$ to parton shower, including top-quark decays with approximate LO spin correlation (see Ref.[2]).