Precision Measurement of CP Violation in B0S→J/ΨK+K− Decays

Autor: Badalov, Alexey, Calvo Gómez, Míriam, Casanova Mohr, Raimon, Garrido Beltrán, Lluís, Gascón Fora, David, Graciani Díaz, Ricardo, Graugés Pous, Eugeni, Marin Benito, Carla, Picatoste Olloqui, Eduardo, Rives Molina, Vicente José, Ruiz, Hugo (Ruiz Pérez), Vilasis-Cardona, Xavier, LHCb Collaboration
Přispěvatelé: Universitat de Barcelona
Rok vydání: 2015
Předmět:
Zdroj: Dipòsit Digital de la UB
Universidad de Barcelona
Recercat. Dipósit de la Recerca de Catalunya
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Popis: The time-dependent C P asymmetry in B 0 s → J / ψ K + K − decays is measured using p p collision data, corresponding to an integrated luminosity of 3.0 fb − 1 , collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV. In a sample of 96 000 B 0 s → J / ψ K + K − decays, the C P -violating phase ϕ s is measured, as well as the decay widths Γ L and Γ H of the light and heavy mass eigenstates of the B 0 s - ¯ B 0 s system. The values obtained are ϕ s = − 0.058 ± 0.049 ± 0.006 rad , Γ s ≡ ( Γ L + Γ H ) / 2 = 0.6603 ± 0.0027 ± 0.0015 ps − 1 , and Δ Γ s ≡ Γ L − Γ H = 0.0805 ± 0.0091 ± 0.0032 ps − 1 , where the first uncertainty is statistical and the second, systematic. These are the most precise single measurements of those quantities to date. A combined analysis with B 0 s → J / ψ π + π − decays gives ϕ s = − 0.010 ± 0.039 rad . All measurements are in agreement with the standard model predictions. For the first time, the phase ϕ s is measured independently for each polarization state of the K + K − system and shows no evidence for polarization dependence.
Databáze: OpenAIRE