Measurement of the t(t)over-bar gamma production cross section in proton-proton collisions at root s=8 TeV with the ATLAS detector

Adersberger, M.; Bender, M.; Biebel, O.; Bock, C.; Bogavac, D.; Duckeck, G.; Flierl, B. M.; Hartmann, N. M.; Heinrich, J. J.; Hertenberger, R.; Hönig, F.; Legger, F.; Lorenz, J.; Lösel, P. J.; Maier, T.; Mann, A.; Mehlhase, S.; Mitrevski, J.; Müller, R. S. P.; Schachtner, B. M.; Rauscher, F.; Schaile, D.; Unverdorben, C.; Valderanis, C.; Wagner-Kuhr, J. und Walker, R. (2017): Measurement of the t(t)over-bar gamma production cross section in proton-proton collisions at root s=8 TeV with the ATLAS detector. In: Journal of High Energy Physics, No. 11, 86

Abstract

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.

• Item Type: Journal article
• Faculties: Physics
• Subjects: 500 Science > 530 Physics
• ISSN: 1029-8479
• Language: English