Measurement of the production cross section of an isolated photon associated with jets in proton-proton collisions at root s=7 TeV with the ATLAS detector

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Aad G., Abbott B., Abdallah J., Abdelalim A. A., Abdesselam A., Abdinov O., ...More

PHYSICAL REVIEW D, vol.85, no.9, 2012 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 85 Issue: 9
  • Publication Date: 2012
  • Doi Number: 10.1103/physrevd.85.092014
  • Journal Name: PHYSICAL REVIEW D
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Middle East Technical University Affiliated: Yes


A measurement of the cross section for the production of an isolated photon in association with jets in proton-proton collisions at a center-of-mass energy root s = 7 TeV is presented. Photons are reconstructed in the pseudorapidity range vertical bar eta(gamma)vertical bar < 1.37 and with a transverse energy E-T(gamma) > 25 GeV. Jets are reconstructed in the rapidity range vertical bar y(jet)vertical bar < 4.4 and with a transverse momentum p(T)(jet) > 20 GeV. The differential cross section d sigma/dE(T)(gamma) is measured, as a function of the photon transverse energy, for three different rapidity ranges of the leading-p(T) jet: vertical bar y(jet)vertical bar < 1.2, 1.2 <= vertical bar y(jet)vertical bar < 2.8 and 2.8 <= vertical bar y(jet)vertical bar < 4.4. For each rapidity configuration the same-sign (eta(gamma)y(jet) >= 0) and opposite-sign (eta(gamma) y(jet) < 0) cases are studied separately. The results are based on an integrated luminosity of 37 pb(-1), collected with the ATLAS detector at the LHC. Next-to-leading order perturbative QCD calculations are found to be in fair agreement with the data, except for E-T(gamma) <= 45 GeV, where the theoretical predictions overestimate the measured cross sections.