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


Aaboud M., Aad G., Abbott B., Abdinov O., Abeloos B., Abidi S. H. , ...More

JOURNAL OF HIGH ENERGY PHYSICS, no.11, 2017 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: Issue: 11
  • Publication Date: 2017
  • Doi Number: 10.1007/jhep11(2017)086
  • Title of Journal : JOURNAL OF HIGH ENERGY PHYSICS

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.