Electron and Photon Reconstruction and Identification with the ATLAS Detector

Abstract

This article presents the electron and photon reconstruction performance of the ATLAS detector based on the first LHC collision data at s = 7 TeV . Calorimetric and tracker related electron identification variables are in a fair agreement with the Monte Carlo model describing the detector response. The position of the reconstructed photon conversions vertices has been used to compare the description of the inner detector used in Monte Carlo geometry to that from data. The energy flow measured in the electromagnetic calorimeter has been used to provide the same comparison at larger radii. π 0 → γ γ and J / Ψ → e + e − peaks were observed with reconstructed masses in good agreement with both Monte Carlo and PDG values. 17 W → e ν candidates and one Z → e + e − candidate have been observed in 6.69 nb-1 of data.