PT Journal AU ATLAS Collaboration (Aad, Gea Amoros, G Cabrera Urban, S Castillo Gimenez, V Costa, MJ Ferrer, A Fiorini, L Fuster, J Garcia, C Garcia Navarro, JE Gonzalez de la Hoz, S Hernandez Jimenez, Y Higon-Rodriguez, E Irles Quiles, A Kaci, M Lacasta, C Lacuesta, VR Marti-Garcia, S Miñano, M Mitsou, VA Moles-Valls, R Moreno Llacer, M Oliver Garcia, E Perez Garcia-Estañ, MT Romero Adam, E Ros, E Salt, J Sanchez Martinez, V Solans, CA Soldevila, U Sanchez, J Torro Pastor, E Valladolid Gallego, E Valls Ferrer, JA Villaplana Perez, M Vos, M Wildauer, A TI Search for the Standard Model Higgs Boson in the Diphoton Decay Channel with 4.9 fb(-1) of pp Collision Data at root s=7 TeV with ATLAS SO Physical Review Letters JI Phys. Rev. Lett. PY 2012 BP 111803 EP 19pp VL 108 IS 11 DI 10.1103/PhysRevLett.108.111803 LA English AB A search for the standard model Higgs boson is performed in the diphoton decay channel. The data used correspond to an integrated luminosity of 4.9 fb(-1) collected with the ATLAS detector at the Large Hadron Collider in proton-proton collisions at a center-of-mass energy of root s = 7 TeV. In the diphoton mass range 110-150 GeV, the largest excess with respect to the background-only hypothesis is observed at 126.5 GeV, with a local significance of 2.8 standard deviations. Taking the look-elsewhere effect into account in the range 110-150 GeV, this significance becomes 1.5 standard deviations. The standard model Higgs boson is excluded at 95% confidence level in the mass ranges of 113-115 GeV and 134.5-136 GeV. ER