Performance of the Missing Transverse Energy Reconstruction and Calibration in Proton-Proton Collisions at a Center-of-Mass Energy of 7 TeV with the ATLAS Detector

In April and May 2010, the ATLAS experiment collected a large number of proton-proton collision events at a center-of-mass energy of 7 TeV. These data are used to test the performance of the reconstruction and calibration of the missing transverse energy (Etmiss) with up to about 300 GeV total transverse energy accumulated per event and with reconstructed objects at large transverse momentum (pT). The resolution and tails of the missing transverse energy distribution, calibrated using different schemes, are in good agreement with the simulation. The small discrepancies between the data and the Monte Carlo in the Etmiss distribution are more pronounced in events containing high pT jets. Comparisons of results with different calibration methods are shown and demonstrate that the Etmiss reconstruction and calibration are well under control and reach the expected performance.