Measurement of the W-boson helicity in top-quark decays from tt̄ production in lepton+jets events in pp collisions at √s = 7 TeV

The W-boson helicity fractions in top-quark decays are measured with tt¯ events in the lepton+jets final state, using proton-proton collisions at a centre-of-mass energy of 7 TeV, collected in 2011 with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 5.0 fb?1....

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Detalles Bibliográficos
Autores: Chatrchyan, Serguei, Brochero Cifuentes, Javier Andrés|||0000-0003-2093-7856, Cabrillo Bartolomé, José Iban|||0000-0002-0367-4022, Calderón Tazón, Alicia|||0000-0002-7205-2040, Chuang, S. H., Duarte Campderros, Jorge|||0000-0003-0687-5214, Fernández García, Marcos|||0000-0002-4824-1087, Gómez Gramuglio, Gervasio|||0000-0002-1077-6553, González Sánchez, Francisco Javier, Graziano, Alberto, Jordá Lope, Clara, López Virto, María Amparo, Marco de Lucas, Jesús|||0000-0001-7914-8494, Marco de Lucas, Rafael José, Martínez Rivero, Celso, Matorras Weinig, Francisco|||0000-0003-4295-5668, Muñoz Sánchez, Francisca Javiela, Rodrigo Anoro, Teresa, Rodríguez Marrero, Ana Yaiza, Ruiz Jimeno, Alberto|||0000-0002-3639-0368, Scodellaro, Luca|||0000-0002-4974-8330, Vila Álvarez, Iván |||0000-0002-6797-7209, Vilar Cortabitarte, Rocío|||0000-0003-2045-8054
Tipo de recurso: artículo
Fecha de publicación:2013
País:España
Institución:Universidad de Cantabria (UC)
Repositorio:UCrea Repositorio Abierto de la Universidad de Cantabria
Idioma:inglés
OAI Identifier:oai:repositorio.unican.es:10902/25644
Acceso en línea:http://hdl.handle.net/10902/25644
Access Level:acceso abierto
Palabra clave:Hadron-Hadron Scattering
Top physics
Descripción
Sumario:The W-boson helicity fractions in top-quark decays are measured with tt¯ events in the lepton+jets final state, using proton-proton collisions at a centre-of-mass energy of 7 TeV, collected in 2011 with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 5.0 fb?1. The measured fractions of longitudinal, left-, and right-handed helicity are F 0 = 0.682 ± 0.030 (stat.) ± 0.033 (syst.), F L = 0.310 ± 0.022 (stat.) ± 0.022 (syst.), and F R = 0.008 ± 0.012 (stat.) ± 0.014 (syst.), consistent with the standard model predictions. The measured fractions are used to probe the existence of anomalous Wtb couplings. Exclusion limits on the real components of the anomalous couplings g L , g R are also derived.