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

Abstract

A measurement of the inclusive ZZ production cross section and constraints on anomalous triple gauge couplings in proton-proton collisions at s=8 TeV are presented. The analysis is based on a data sample, corresponding to an integrated luminosity of 19.6fb -1, collected with the CMS experiment at the LHC. The measurements are performed in the leptonic decay modes ZZ→ℓℓℓ ' ℓ ', where ℓ = e, μ and ℓ ' = e, μ, τ. The measured total cross section σ(pp→ZZ)=7.7±0.5 (stat)-0.4+0.5 (syst)±0.4(theo)±0.2 (lumi) pb, for both Z bosons produced in the mass range 60 < mZ < 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 ZZγ couplings at the 95% confidence level: -0.004<f4Z<0.004, -0.004<f5Z<0.004, -0.005<f4γ<0.005, and -0.005<f5γ<0.005.