ATLAS collaboration (3034 authors)Aguilar-Saavedra, Juan AntonioAmaral, PedroAnjos, NunoCarvalho, JoaoCastro, Nuno FilipeConde Muino, PatriciaDo Valle Wemans, AndreFiolhais, MiguelGomes, AgostinhoGoncalo, RicardoJorge, PedroLopes, LourencoMachado Miguens, JoanaMagalhaes Martins, Paulo JorgeMaio, AmeliaManeira, JoseMorais, AntonioOliveira, Miguel AlfonsoOnofre, AntonioPalma, AlbertoPina, Joao AntonioPinto, BelmiroSantos, HelenaSaraiva, JoaoSilva, JoseSoares, MaraVeloso, FilipeWolters, Helmut2019-02-032019-02-032011-07http://dx.doi.org/10.1103/PhysRevD.85.012003http://hdl.handle.net/10400.26/26025The ATLAS experiment has measured the production cross-section of events with two isolated photons in the final state, in proton-proton collisions at sqrt(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, total transverse momentum and azimuthal separation, are presented and compared to the predictions of next-to-leading-order QCD.engjournal article2019-02-03