%0 Journal Article %T Measurement of the t(t)over-bar gamma production cross section in proton-proton collisions at root s=8 TeV with the ATLAS detector %A ATLAS Collaboration (Aaboud, M. et al %A Alvarez Piqueras, D. %A Barranco Navarro, L. %A Cabrera Urban, S. %A Castillo Gimenez, V. %A Cerda Alberich, L. %A Costa, M. J. %A Escobar, C. %A Estrada Pastor, O. %A Fernandez Martinez, P. %A Ferrer, A. %A Fiorini, L. %A Fuster, J. %A Garcia, C. %A Garcia Navarro, J. E. %A Gonzalez de la Hoz, S. %A Higon-Rodriguez, E. %A Jimenez Pena, J. %A Lacasta, C. %A Madaffari, D. %A Mamuzic, J. %A Marti-Garcia, S. %A Melini, D. %A Mitsou, V. A. %A Pedraza Lopez, S. %A Rodriguez Bosca, S. %A Rodriguez Rodriguez, D. %A Romero Adam, E. %A Salt, J. %A Sanchez Martinez, V. %A Soldevila, U. %A Sanchez, J. %A Valero, A. %A Valls Ferrer, J. A. %A Vos, M. %J Journal of High Energy Physics %D 2017 %V 11 %N 11 %I Springer %@ 1029-8479 %G English %F ATLASCollaborationAaboud_etal2017 %O WOS:000415660000002 %O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=3381), last updated on Thu, 07 Dec 2017 09:35:00 +0000 %X The cross section of a top-quark pair produced in association with a photon is measured in proton-proton collisions at a centre-of-mass energy of root s = 8 TeV with 20.2 fb(-1) of data collected by the ATLAS detector at the Large Hadron Collider in 2012. The measurement is performed by selecting events that contain a photon with transverse momentum p(T) > 15 GeV, an isolated lepton with large transverse momentum, large missing transverse momentum, and at least four jets, where at least one is identified as originating from a b-quark. The production cross section is measured in a fiducial region close to the selection requirements. It is found to be 139 +/- 7 (stat.) +/- 17 (syst.) fb, in good agreement with the theoretical prediction at next-to-leading order of 151 +/- 24 fb. In addition, differential cross sections in the fiducial region are measured as a function of the transverse momentum and pseudorapidity of the photon. %K Hadron-Hadron scattering (experiments) %K Top physics %R 10.1007/JHEP11(2017)086 %U http://arxiv.org/abs/1706.03046 %U https://doi.org/10.1007/JHEP11(2017)086 %P 086-43pp