Electron Performances in ATLAS

Providing an efficient electron reconstruction and identification over a wide energy range (5 GeV – 1 TeV) is of great importance to the Atlas physics program. During 2012 data-taking, a new reconstruction scheme was exploited, to better describe the loss of energy due to Bremsstrahlung in the detector. The existing cut-based identification menus were re-optimized to cope with the harsher pile-up conditions, and new MVA-based menus were developed, achieving almost doubled rejection power. The accuracy with which the MC models the electron efficiency plays an important role in cross-section measurements and various searches for new physics. In order to achieve reliable physics results, the MC samples need to be corrected to reproduce the measured data efficiencies as closely as possible. Precise efficiency measurement in data and MC over the entire ET range is therefore very important, and it is achieved exploiting two complementary samples, Z→ee and J/ψ→ee, and five different analysis.