Experience in the electron reconstruction with first CMS data

The first CMS data from the center-of-mass energy of 900 GeV proton-proton collisions were analyzed in order to commission electron reconstruction and assess its performance. A comparison between data and simulation of all the key ingredients for the electron physics objects reconstruction and identification was performed. The good agreement shown indicates that the sub-detectors response is well modeled in the simulation and that the algorithms designed and optimized with the simulation are functioning as expected.