The decay-time-dependent CP asymmetry in B0s → J/ψ (→ μ+ μ-) K+ K- decays is measured using proton-proton collision data, corresponding to an integrated luminosity of 6 fb^-1, collected with the LHCb detector at a center-of-mass energy of 13 TeV. Using a sample of approximately 349000 B0s signal decays with an invariant K+ K- mass in the vicinity of the φ(1020) resonance, the CP-violating phase φs is measured, along with the difference in decay widths of the light and heavy mass eigenstates of the B0s-anti-B0s system, ΔΓs, and the difference of the average B0s and B0 meson decay widths, Γs - Γd. The values obtained are φs = -0.039 ± 0.022 ± 0.006 rad, ΔΓs = 0.0845 ± 0.0044 ± 0.0024 ps^-1, and Γs - Γd = -0.056{-0.0015}{+0.0013} ± 0.0014 ps^-1, where the first uncertainty is statistical and the second systematic. These are the most precise single measurements to date and are consistent with expectations based on the Standard Model and with the previous LHCb analyses of this decay. These results are combined with previous independent LHCb measurements. The phase φs is also measured independently for each polarization state of the K+ K- system and shows no evidence for polarization dependence.

Aaij, R., Abdelmotteleb, A. . ., Abellan Beteta, C., Abudinén, F., Ackernley, T., Adeva, B., et al. (2024). Improved Measurement of CP Violation Parameters in B0s → J/ψ K+ K− Decays in the Vicinity of the ϕ(1020) Resonance. PHYSICAL REVIEW LETTERS, 132(5), 1-12 [10.1103/physrevlett.132.051802].

Improved Measurement of CP Violation Parameters in B0s → J/ψ K+ K− Decays in the Vicinity of the ϕ(1020) Resonance

Carbone, A.;Ferrari, F.;Galli, D.;Patrignani, C.;Spedicato, E.;Villa, A.;
2024

Abstract

The decay-time-dependent CP asymmetry in B0s → J/ψ (→ μ+ μ-) K+ K- decays is measured using proton-proton collision data, corresponding to an integrated luminosity of 6 fb^-1, collected with the LHCb detector at a center-of-mass energy of 13 TeV. Using a sample of approximately 349000 B0s signal decays with an invariant K+ K- mass in the vicinity of the φ(1020) resonance, the CP-violating phase φs is measured, along with the difference in decay widths of the light and heavy mass eigenstates of the B0s-anti-B0s system, ΔΓs, and the difference of the average B0s and B0 meson decay widths, Γs - Γd. The values obtained are φs = -0.039 ± 0.022 ± 0.006 rad, ΔΓs = 0.0845 ± 0.0044 ± 0.0024 ps^-1, and Γs - Γd = -0.056{-0.0015}{+0.0013} ± 0.0014 ps^-1, where the first uncertainty is statistical and the second systematic. These are the most precise single measurements to date and are consistent with expectations based on the Standard Model and with the previous LHCb analyses of this decay. These results are combined with previous independent LHCb measurements. The phase φs is also measured independently for each polarization state of the K+ K- system and shows no evidence for polarization dependence.
2024
Aaij, R., Abdelmotteleb, A. . ., Abellan Beteta, C., Abudinén, F., Ackernley, T., Adeva, B., et al. (2024). Improved Measurement of CP Violation Parameters in B0s → J/ψ K+ K− Decays in the Vicinity of the ϕ(1020) Resonance. PHYSICAL REVIEW LETTERS, 132(5), 1-12 [10.1103/physrevlett.132.051802].
Aaij, R.; Abdelmotteleb, A.  S.  W.; Abellan Beteta, C.; Abudinén, F.; Ackernley, T.; Adeva, B.; Adinolfi, M.; Adlarson, P.; Afsharnia, H.; Agapopoulo...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/1001594
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