Measurement of ZZ production in pp collisions at s√=7 TeV and limits on anomalous ZZZ and ZZγ couplings with the ATLAS detector

• Autor(a) principal: Onofre, A.
• Data de Publicação: 2013
• Outros Autores: Castro, Nuno Filipe Silva Fernandes, ATLAS Collaboration
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/32020
• topic: Hadron-Hadron Scattering; Ciências Naturais::Ciências Físicas; Science & Technology

A measurement of the ZZ production cross section in proton-proton collisions at √ s = 7 TeV using data recorded by the ATLAS experiment at the Large Hadron Collider is presented. In a data sample corresponding to an integrated luminosity of 4.6 fb−1 collected in 2011, events are selected that are consistent either with two Z bosons decaying to electrons or muons or with one Z boson decaying to electrons or muons and a second Z boson decaying to neutrinos. The ZZ(∗) → ` +` −` 0+` 0− and ZZ → ` +` −νν¯ cross sections are measured in restricted phase-space regions. These results are then used to derive the total cross section for ZZ events produced with both Z bosons in the mass range 66 to 116 GeV, σ tot ZZ = 6.7 ± 0.7 (stat.) +0.4 −0.3 (syst.) ± 0.3 (lumi.) pb, which is consistent with the Standard Model prediction of 5.89+0.22 −0.18 pb calculated at next-to-leading order in QCD. The normalized differential cross sections in bins of various kinematic variables are presented. Finally, 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.