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oai:recercat.cat:2445/1318402025-12-05T16:49:36Zcom_2072_1057col_2072_478823col_2072_478904col_2072_478917

urn:hdl:2445/131840 Measurement of CP violation and the B0s meson decay width difference with B0s → J/ψK+K− and B0s → J/ψπ+π− decays Abellan Beteta, Carlos Calvo Gómez, Míriam Camboni, Alessandro Comerma Montells, Albert Garrido Beltrán, Lluís Graciani Díaz, Ricardo Graugés Pous, Eugeni López Asamar, Elias Oyanguren Campos, Arantza de Pérez-Calero Yzquierdo, Antonio Picatoste Olloqui, Eduardo Potterat, Cédric Rives Molina, Vicente José Ruiz, Hugo (Ruiz Pérez) Ruiz Valls, Pablo Vázquez Gómez, Ricard Vilasis-Cardona, Xavier LHCb Collaboration Física de partícules Experiments Violació CP (Física nuclear) Particle physics Experiments CP violation (Nuclear physics) The time-dependent C P asymmetry in B 0 s → J / ψ K + K − decays is measured using p p collision data at √ s = 7     TeV , corresponding to an integrated luminosity of 1.0     fb − 1 , collected with the LHCb detector. The decay-time distribution is characterized by the decay widths Γ L and Γ H of the light and heavy mass eigenstates of the B 0 s − ¯¯¯ B 0 s system and by a C P -violating phase ϕ s . In a sample of 27 617 B 0 s → J / ψ K + K − decays, where the dominant contribution comes from B 0 s → J / ψ ϕ decays, these parameters are measured to be ϕ s = 0.07 ± 0.09 ( stat ) ± 0.01 ( syst )     rad , Γ s ≡ ( Γ L + Γ H ) / 2 = 0.663 ± 0.005 ( stat ) ± 0.006 ( syst )     ps − 1 , and Δ Γ s ≡ Γ L − Γ H = 0.100 ± 0.016 ( stat ) ± 0.003 ( syst )     ps − 1 , corresponding to the single most precise determination of ϕ s , Δ Γ s , and Γ s . The result of performing a combined analysis with B 0 s → J / ψ π + π − decays gives ϕ s = 0.01 ± 0.07 ( stat ) ± 0.01 ( syst )     rad , Γ s = 0.661 ± 0.004 ( stat ) ± 0.006 ( syst )     ps − 1 , and Δ Γ s = 0.106 ± 0.011 ( stat ) ± 0.007 ( syst )     ps − 1 . All measurements are in agreement with the Standard Model predictions. 2019-04-08T13:52:59Z 2019-04-08T13:52:59Z 2013-06-21 2019-04-08T13:52:59Z info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Reproducció del document publicat a: https://doi.org/10.1103/PhysRevD.87.112010 Physical Review D, 2013, vol. 87, num. 11, p. 112010 https://doi.org/10.1103/PhysRevD.87.112010 cc by (c) CERN; LHCb Collaboration, 2013 http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess American Physical Society Articles publicats en revistes (Física Quàntica i Astrofísica)