Data Driven Estimates of Dilepton Final State Backgrounds in ATLAS

The Large Hadron Collider at the international particle physics laboratory CERN in Switzerland is currently the most powerful particle accelerator on earth. Protons are collided at an energy of sqrt(s) = 7 TeV. The goal is to find new phenomena not described by the Standard Model of particle physics. ATLAS is one of the detectors that record the collision processes. Many processes will result in high energy leptons (electrons and muons), measured by ATLAS. A significant fraction of the recorded leptons are however produced in background processes that are difficult to model in simulations. A general method using data will be described that estimates the background due to mis-identified leptons. An estimate of the mis-identified lepton background will be used in an analysis that simultaneously measures the cross-sections of three important Standard Model processes.