Measurement of the pp to ZZ production cross section and constraints on anomalous triple gauge couplings in four-lepton final states at sqrt(s) = 8 TeV

A measurement of inclusive ZZ production cross section and constraints on anomalous triple gauge couplings in proton-proton collisions at sqrt(s) = 8 TeV are presented. A data sample, corresponding to an integrated luminosity of 19.6 inverse-femtobarns was collected with the CMS experiment at the LHC. The measurements are performed in the leptonic decay modes ZZ to lll'l', where l = e, mu and l' = e, mu, tau. The measured total cross section, sigma (pp to ZZ) = 7.7 +/-0.5 (stat) +0.5-0.4 (syst) +/- 0.4 (theo) +/- 0.2 (lum) pb for both Z bosons produced in the mass range m_Z within 60 and 120 GeV, is consistent with standard model predictions. Differential cross sections are measured and well described by the theoretical predictions. The invariant mass distribution of the four-lepton system is used to set limits on anomalous ZZZ and ZZgamma couplings at the 95% confidence level: f_4^Z in (-0.004,+0.004), f_5^Z in (-0.005,+0.005), f_4^gamma in (-0.004,+0.004), and f_5^gamma in (-0.005,+0.005).