Measurement of the isolated diphoton cross section in pp collisions at √s = 7 TeV with the ATLAS detector

The ATLAS experiment has measured the production cross section of events with two isolated photons in the final state, in proton-proton collisions at √s = 7  TeV. The full data set acquired in 2010 is used, corresponding to an integrated luminosity of 37  pb-1. The background, consisting of hadronic jets and isolated electrons, is estimated with fully data-driven techniques and subtracted. The differential cross sections, as functions of the di-photon mass (mγγ), total transverse momentum (pT,γγ), and azimuthal separation (Δϕγγ), are presented and compared to the predictions of next-to-leading-order QCD.