Measurements of isolated prompt photons in pp collisions with the ATLAS detector

ATLAS has measured the production cross section of events with one and two isolated prompt photons in the final state, in proton-proton collisions at a center-of-mass energy $sqrt{s}=7$ TeV. The results presented here are based on the full data set collected in 2010 with the ATLAS detector at the Large Hadron Collider. Photon candidates are identified by combining information from the calorimeters and from the inner tracker. Residual background in the selected sample is estimated from data, based on the observed distribution of the transverse isolation energy in a narrow cone around the photon candidate. The results are compared to predictions from next-to-leading order perturbative QCD calculations.