Performance of Tau Identification and Associated Systematic Uncertainties in ATLAS

In these proceedings, a description of the reconstruction and identification methods for tau leptons in ATLAS at the LHC is presented. Identifying tau leptons is essential in many analyses, be it for Standard Model (SM) and Higgs boson signatures or searches for physics beyond the SM. The decay of the tau particle with leptonic as well as hadronic decay modes and its short lifetime makes it especially challenging to identify this lepton. After a short introduction about the tau lepton and its reconstruction in ATLAS, three different tau identification methods are presented in more detail. The identification efficiencies and their systematic uncertainties for 2010 data analysis in ATLAS are evaluated and discussed here. XXIst International Europhysics Conference on High Energy Physics 21-27 July 2011 Grenoble, Rhône-Alpes France ∗Speaker. †On behalf of the ATLAS Collaboration. c © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. http://pos.sissa.it/ P o S ( E P S H E P 2 0 1 1 ) 4 7 0 Performance of Tau Identification and Associated Systematic Uncertainties in ATLAS Frank SEIFERT