Next-to-next-to-leading order event generation for Z-boson pair production matched to parton shower

We present a novel next-to-next-to-leading order (NNLO) QCD calculation matched to parton shower for the production of a pair of Z bosons decaying to four massless leptons, pp -> l(+) l(-) l'(+) l'(-) + X, at the LHC. Spin correlations, interferences and off-shell effects are included throughout. Our result is based on the resummed beam-thrust spectrum, which we evaluate at next-to-next-to-leading-logarithmic (NNLLT0') accuracy for the first time for this process, and makes use of the GENEVA Monte Carlo framework for the matching to PYTHIA8 shower and hadronisation models. We compare our predictions with data from the ATLAS and CMS experiments at 13 TeV, finding a good agreement. (C) 2021 The Author(s). Published by Elsevier B.V.

Automated summary

A novel NNLO QCD calculation method matched to parton shower was proposed for the production of Z bosons decaying into four massless leptons at the LHC. The results show a good agreement with data from the ATLAS and CMS experiments, indicating the effectiveness of the method.