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

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)^+0.5_−0.4 (syst) ±0.4 (theo) ±0.2 (lumi) pb, for both Z bosons produced in the mass range 60 < m_Z <120GeV, 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 < f^Z₄ < 0.004, −0.004 < f^Z₅ < 0.004, −0.005 < f^γ₄ < 0.005, and −0.005 <f^γ₅<0.005.