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


Aaij R., Adeva B., Adinolfi M., Affolder A., Ajaltouni Z., Akar S., ...More

Physical Review Letters, vol.114, no.4, 2015 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 114 Issue: 4
  • Publication Date: 2015
  • Doi Number: 10.1103/physrevlett.114.041801
  • Journal Name: Physical Review Letters
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Manisa Celal Bayar University Affiliated: Yes

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.