Measurement of isolated photon production at CMS in pp collisions at sqrt(s)=7 TeV

We present the preliminary results on commissioning of photon reconstruction and identification toward the isolated photon production in the CMS experiment using 74 $\rm{nb^{-1}}$ data collected in proton-proton collisions at $\sqrt{s} = 7~\rm{TeV}$. In order to identify isolated photons, the contribution of background from jets and hadron decays, such as $\pi^0$ decays to two photons, are estimated with several variables, including the shower shape measured in the electromagnetic calorimeter (ECAL), the isolation measured in tracker and calorimeter, and the ratio of momentum measured in the tracker to the energy measured in the ECAL for converted photons. The results present the isolated photon production as expected from Monte-Carlo.