Abstract: Four-lepton production in proton?proton collisions, pp?(Z/??)(Z/??)?+?+?, where , =eor ?, is studied at a center-of-mass energy of 13TeV with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 2.6fb?1. The ZZ production cross section, ?(pp?ZZ) =14.6+1.9?1.8(stat) +0.5?0.3(syst) ±0.2 (theo)±0.4 (lumi) pb, is measured for events with two opposite-sign, same-flavor lepton pairs produced in the mass region 60 4GeVfor all opposite-sign, same-flavor lepton pairs. The results are in agreement with standard model predictions.
