Calibration of the CMS electromagnetic calorimeter with √s = 7 TeV LHC collisions data

The √s = 7 TeV LHC collisions recorded with the CMS detector have been used to perform a channel-by-channel calibration of the electromagnetic calorimeter (ECAL). With 2010 data, decays of π⁰ and η into two photons as well as the azimuthal symmetry of the average energy deposition at a given pseudorapidity are used to equalize the response of the individual channels. Based on 36 pb^™1 of collected luminosity, results will be shown for each method and for the combination. Finally, the energy scale of the ECAL has been investigated and comparison with the simulation predictions has been made.