Leptonic fake rates from jets at ATLAS

With first data, the ATLAS detector may be used to look for evidence of new physics in many different processes with leptons in the final state. In order to search for interesting new physics, it will be necessary to understand and eliminate sources of background. One source of background arises from events in which jets are falsely reconstructed as leptons. This fake rate has been calculated for both electrons and muons using simulated data. The rate at which jets fake electrons has also been calculated using data-driven techniques in W events.