The time-dependent CP asymmetry in Bs0→J/ψK+K- decays is measured using pp collision data, corresponding to an integrated luminosity of 3.0fb-1, collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV. In a sample of 96000 Bs0→J/ψK+K- decays, the CP-violating phase φs is measured, as well as the decay widths ΓL and ΓH of the light and heavy mass eigenstates of the Bs0-B¯s0 system. The values obtained are φs=-0.058±0.049±0.006rad, Γs≡(ΓL+ΓH)/2=0.6603±0.0027±0.0015ps-1, and ΔΓs≡ΓL-ΓH=0.0805±0.0091±0.0032ps-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 Bs0→J/ψπ+π- decays gives φs=-0.010±0.039rad. All measurements are in agreement with the standard model predictions. For the first time, the phase φs is measured independently for each polarization state of the K+K- system and shows no evidence for polarization dependence.

Aaij, R., Adeva, B., Adinolfi, M., Affolder, A., Ajaltouni, Z., Akar, S., et al. (2015). Precision measurement of CP violation in BS0 →j / Ψk+K- decays. PHYSICAL REVIEW LETTERS, 114(4) [10.1103/PhysRevLett.114.041801].

Precision measurement of CP violation in BS0 →j / Ψk+K- decays

Borsato, M;CALVI, MARTA;CASSINA, LORENZO;GOTTI, CLAUDIO;KHANJI, BASEM;Martinelli, M;
2015

Abstract

The time-dependent CP asymmetry in Bs0→J/ψK+K- decays is measured using pp collision data, corresponding to an integrated luminosity of 3.0fb-1, collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV. In a sample of 96000 Bs0→J/ψK+K- decays, the CP-violating phase φs is measured, as well as the decay widths ΓL and ΓH of the light and heavy mass eigenstates of the Bs0-B¯s0 system. The values obtained are φs=-0.058±0.049±0.006rad, Γs≡(ΓL+ΓH)/2=0.6603±0.0027±0.0015ps-1, and ΔΓs≡ΓL-ΓH=0.0805±0.0091±0.0032ps-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 Bs0→J/ψπ+π- decays gives φs=-0.010±0.039rad. All measurements are in agreement with the standard model predictions. For the first time, the phase φs is measured independently for each polarization state of the K+K- system and shows no evidence for polarization dependence.
Articolo in rivista - Articolo scientifico
Flavour Physics, LHC collider, CP violation
English
2015
114
4
041801
none
Aaij, R., Adeva, B., Adinolfi, M., Affolder, A., Ajaltouni, Z., Akar, S., et al. (2015). Precision measurement of CP violation in BS0 →j / Ψk+K- decays. PHYSICAL REVIEW LETTERS, 114(4) [10.1103/PhysRevLett.114.041801].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/96732
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