Measurements of pp → ZZ production cross sections and constraints on anomalous triple gauge couplings at √s = 13 TeV

Abstract

The production of Z boson pairs in proton–proton ( \(pp\) ) collisions, \(pp\to \left(Z/{\gamma }^{\ast }\right)\left(Z/{\gamma }^{\ast }\right)\to 2\ell 2{\ell }^{\prime }\), where \(\ell,{\ell }^{\prime }=e\) or \(\mu \), is studied at a center-of-mass energy of 13 \(\phantom{\rule{0.166667em}{0ex}}\text{TeV}\) with the CMS detector at the CERN LHC. The data sample corresponds to an integrated luminosity of 137 \(\phantom{\rule{0.166667em}{0ex}}{\text{fb}}^{-1}\), collected during 2016–2018. The \(ZZ\) production cross section, \({\sigma }_{\text{tot}}\left(pp\to ZZ\right)=17.4±0.3\phantom{\rule{0.166667em}{0ex}}\text{(stat)}±0.5\phantom{\rule{0.166667em}{0ex}}\text{(syst)}±0.4\phantom{\rule{0.166667em}{0ex}}\text{(theo)}±0.3\phantom{\rule{0.166667em}{0ex}}\text{(lumi) pb}\), measured for events with two pairs of opposite-sign, same-flavor leptons produced in the mass region \(60<{m}_{{\ell }^{+}{\ell }^{-}}<120\phantom{\rule{0.166667em}{0ex}}\text{GeV}\) is consistent with standard model predictions. Differential cross sections are also measured and agree with theoretical predictions. The invariant mass distribution of the four-lepton system is used to set limits on anomalous \(ZZZ\) and \(ZZ\gamma \) couplings.