Abstract
The production of Z boson pairs in proton-proton (pp) collisions, pp → (Z/γ*)(Z/γ*) → 2ℓ 2ℓ′, where ℓ,ℓ′ = e or μ, is studied at a center-of-mass energy of 13 TeV with the CMS detector at the CERN LHC. The data sample corresponds to an integrated luminosity of 137 fb−1, collected during 2016-2018. The ZZ production cross section, σtot (pp → ZZ) = 17.2 ± 0.3 (stat) ± 0.5 (syst) ± 0.4 (theo) ± 0.3 (lumi) pb, measured for events with two pairs of opposite-sign, same-flavor leptons produced in the mass region 60 < mℓ+ℓ− < 120 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 ZZγ couplings.
