Measurement of the ZZ production cross section in pp collisions at sqrt(s) = 8 TeV using the ZZ -> l-l+l'-l'+ and ZZ -> l-l+ nu nu¯ channels with the ATLAS detector

A measurement of the ZZ production in the ℓ−ℓ+ℓ′−ℓ′+ and ℓ−ℓ+νν¯ channels (ℓ=e,μ) in proton--proton collisions at s√=8 TeV at the Large Hadron Collider at CERN, using data corresponding to an integrated luminosity of 20.3 fb−1 collected by the ATLAS experiment in 2012 is presented. The fiducial cross sections for ZZ→ℓ−ℓ+ℓ′−ℓ′+ and ZZ→ℓ−ℓ+νν¯ are measured in selected phase-space regions. The total cross section for ZZ events produced with both Z bosons in the mass range 66 to 116 GeV is measured from the combination of the two channels to be 7.3±0.4(stat)±0.3(syst)±0.2(lumi) pb, which is consistent with the Standard Model prediction of 6.6+0.7−0.6 pb. The differential cross sections in bins of various kinematic variables are presented. The differential event yield as a function of the transverse momentum of the leading Z boson is used to set limits on anomalous neutral triple gauge boson couplings in ZZ production.