The trigger and offline reconstruction, identification and energy calibration algorithms employed for hadronic decays of tau leptons for the data collected in 2012 with the ATLAS detector at the LHC operating at a center-of-mass energy of 8TeV are described. The performance of these algorithms is measured in most cases with Z decays to tau leptons. An uncertainty on the offline reconstructed tau energy scale of about 2-4% is achieved using two independent methods. The offline tau identification efficiency is measured with a precision of (2-3)% for hadronically decaying tau leptons with one associated track, and of (4-5)% for the case of three associated tracks, inclusive in η and for a visible transverse momentum greater than 20 GeV. Stability of the performance and through the data taking period is observed with respect to the number of concurrent proton-proton interactions.
Collaboration ATLAS (CERN)