Measurement of the bottom-strange meson mixing phase in the full CDF data set

We report a measurement of the bottom-strange meson mixing phase β s using the time evolution of Bs0→J/ ψ(→μ +μ -)(→K +K -) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at √s=1.96TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6fb -1 of integrated luminosity. We report confidence regions in the two-dimensional space of β s and the Bs0 decay-width difference ΔΓ s and measure β s [-π/2,-1.51] [-0.06,0.30] [1.26,π/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of β s, we also determine ΔΓ s=0.068±0. 026(stat)±0.009(syst)ps -1 and the mean Bs0 lifetime τ s=1.528±0.019(stat)±0.009(syst)ps, which are consistent and competitive with determinations by other experiments.