Reconstruction and Calibration of Missing Transverse Energy and Performance in Z and W events in ATLAS Proton-Proton Collisions at 7 TeV

The missing transverse energy (etmiss) is studied in Wln and Zll events (where l is an electron or muon) selected in 2010 proton-proton collisions at a center-of-mass energy of 7 TeV collected by the ATLAS experiment. These data, corresponding to an integrated luminosity of about 35pb-1, are used to test the performance of the reconstructed etmiss with the refined calibration. Different configurations of the refined calibration are compared and the one displaying the optimal performance is recommended for future physics analyses. The performance of this recommended etmiss in data is compared with the expectations from simulation and good agreement is seen. A first study of the absolute etmiss scale is performed using Wln events containing genuine etmiss originating from the neutrino. A preliminary estimate of the systematic uncertainty on the etmiss scale is also given.