Updated measurement of time-dependent CP -violating observables in Bs0→J/ψK+ K- decays

The LHCb Collaboration

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)

Abstract

The decay-time-dependent CP asymmetry in Bs0→J/ψK+K- decays is measured using proton–proton collision data, corresponding to an integrated luminosity of 1.9fb-1, collected with the LHCb detector at a centre-of-mass energy of 13TeV in 2015 and 2016. Using a sample of approximately 117 000 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 Bs0-B¯s0 system, Δ Γ s. The difference of the average Bs0 and B meson decay widths, Γ s- Γ d, is determined using in addition a sample of B→ J/ ψK+π- decays. The values obtained are ϕs=-0.083±0.041±0.006rad, ΔΓs=0.077±0.008±0.003ps-1 and Γs-Γd=-0.0041±0.0024±0.0015ps-1, where the first uncertainty is statistical and the second systematic. These are the most precise single measurements of these quantities to date and are consistent with expectations based on the Standard Model and with a previous LHCb analysis of this decay using data recorded at centre-of-mass energies 7 and 8 TeV. Finally, the results are combined with recent results from Bs0→J/ψπ+π- decays obtained using the same dataset as this analysis, and with previous independent LHCb results.

Original languageEnglish
Article number706
Number of pages26
JournalEuropean Physical Journal C
Volume79
Issue number8
DOIs
Publication statusPublished - 1 Aug 2019

Keywords

  • WIDTH DIFFERENCE
  • PHASE PHI(S)
  • PRECISION
  • BEAUTY
  • TOOL

Fingerprint

Dive into the research topics of 'Updated measurement of time-dependent CP -violating observables in Bs0→J/ψ<sup>K+</sup> <sup>K-</sup> decays'. Together they form a unique fingerprint.

Cite this