Measurement of the production of a <i>W</i> boson in association with a charm quark in <i>pp</i> collisions at √s=7 TeV with the ATLAS detector


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Aad G., Abajyan T., Abbott B., Abdallah J., Abdel Khalek S., Abdinov O., ...More

JOURNAL OF HIGH ENERGY PHYSICS, no.5, pp.1-67, 2014 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Publication Date: 2014
  • Doi Number: 10.1007/jhep05(2014)068
  • Journal Name: JOURNAL OF HIGH ENERGY PHYSICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1-67
  • Keywords: Charm physics, Electroweak interaction, Hadron-Hadron scattering
  • Ankara University Affiliated: Yes

Abstract

The production of a W boson in association with a single charm quark is studied using 4.6 fb(-1) of pp collision data at root s = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96(-0.30)(+0.26) at Q (2) = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio sigma(W (+) +)/sigma(W (-) + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s-(s) over bar quark asymmetry.