Measurement of the production of a W boson in association with a charm quark in pp collisions at sqrt(s)=7 TeV with the ATLAS detector

• Autores: Aad, G.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Otero y Garzon, Gustavo Javier; Piegaia, Ricardo Nestor; Sacerdoti, Sabrina; Reisin, Hernan Diego; Alconada Verzini, María Josefina; Alonso, Francisco; Anduaga, Xabier Sebastian; Arduh, Francisco Anuar; Dova, Maria Teresa; Monticelli, Fernando Gabriel; Wahlberg, Hernan Pablo; Zhukov, K.; Zibell, A.; Zieminska, D.; Zimine, N. I.; Zimmermann, C.; Zimmermann, R.; Zimmermann, S.; Zimmermann, S.; Ziolkowski, M.; Zobernig, G.; Zoccoli, A.; Nedden, M. zur; Zurzolo, G.; Zutshi, V.; Zwalinski, L.; The ATLAS Collaborationx
• Año de publicación: 2014
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: ATLAS; Particle; Physics
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

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 sqrt(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 +0.26 -0.30 at Q^2=1.9 GeV^2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio sigma(W^+ + bar{c})/sigma(W^- + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s-bar{s} quark asymmetry.
Fil: ATLAS Collaboration, G. AAd, F. Monticelli, et al. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Cern - European Organization For Nuclear Research; Suiza