Measurements of $ZZ \rightarrow \ell\ell\nu\nu$ and $ZZjj \rightarrow \ell\ell\nu\nu jj$ productions in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

TL;DR

This paper reports precise measurements of $ZZ$ and $ZZjj$ production cross-sections at 13 TeV with the ATLAS detector, confirming Standard Model predictions and setting limits on anomalous gauge couplings.

Contribution

First detailed measurements of $ZZ$ and $ZZjj$ production at 13 TeV with extensive differential analysis and constraints on anomalous gauge interactions.

Findings

Measured inclusive $ZZ$ cross-section: 21.0±1.0 fb.

Measured $ZZjj$ cross-section: 0.96+0.18−0.16 fb.

Results agree with Standard Model predictions.

Abstract

This article presents measurements of $Z$ boson pair production cross-sections at a center-of-mass energy of $\sqrt{s} = 13$ TeV, using 140 fb$^{-1}$ of proton-proton data collected with the ATLAS detector at the Large Hadron Collider. The analysis includes both inclusive $ZZ$ production and $ZZ$ production in association with two jets ($ZZjj$), where one $Z$ boson decays into a pair of charged leptons $\ell^+\ell^-$ ($\ell = e, \mu$), and the other decays into a neutrino pair. The measured fiducial cross-section of the inclusive $ZZ$ production is $21.0\pm1.0$ fb, while for the $ZZjj$ production it is $0.96^{+0.18}_{-0.16}$ fb. Extrapolation of the $ZZ$ cross-section to the full phase space, for $Z$ bosons within the mass range $66-116$~GeV, yields $\sigma (pp \rightarrow ZZ) = 15.38\pm0.81$ pb. Differential cross-sections are presented for an extended set of kinematic observables. The results are found to be in good agreement with Standard Model predictions. Constraints on anomalous gauge boson self-interactions are derived using both the vertex function formalism and the effective field theory framework.