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

The production of Z boson pairs in proton–proton (p p) collisions, p p → (Z / γ ^∗) (Z / γ ^∗) → 2 ℓ2 ℓ ^′, where ℓ, ℓ ^′= e or μ , is studied at a center-of-mass energy of 13TeV with the CMS detector at the CERN LHC. The data sample corresponds to an integrated luminosity of 137fb-1, collected during 2016–2018. The Z Z production cross section, σtot(pp→ZZ)=17.4±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-<120GeV 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 Z Z Z and Z Z γ couplings.