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

• 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 349 000 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−¯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=−0.0056+0.0013−0.0015±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.

Ämnesord

NATURVETENSKAP  -- Fysik -- Subatomär fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Subatomic Physics (hsv//eng)

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)