Measurement of the Z -> tau tau cross section with the ATLAS detector

• Autor(a) principal: Onofre, A.
• Data de Publicação: 2011
• 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/1822/48743
• topic: Ciências Naturais::Ciências Físicas; Ciências Naturais::Ciências Físicas; Science & Technology

The Z→ττ cross section is measured with the ATLAS experiment at the LHC in four different final states determined by the decay modes of the τ leptons: muon-hadron, electron-hadron, electron-muon, and muon-muon. The analysis is based on a data sample corresponding to an integrated luminosity of 36  pb−1, at a proton-proton center-of-mass energy of s=7  TeV. Cross sections are measured separately for each final state in fiducial regions of high detector acceptance, as well as in the full phase space, over the mass region 66–116 GeV. The individual cross sections are combined and the product of the total Z production cross section and Z→ττ branching fraction is measured to be 0.97±0.07(stat)±0.06(syst)±0.03(lumi)  nb, in agreement with next-to-next-to-leading order calculations.