Measurement of Lifetime and Decay-Width Difference in B0s → J/ψØ Decays

We measure the mean lifetime τ = 2/(ΓL + ΓT H ) and the decay-width difference AF = Γ L - Γ H of the light and heavy mass eigenstates of the B 0 s , meson, B 0 sL and B 0 s H, in B) 0 s →J/ψ∅ decays using 1.7 fb -1 of data collected with the CDF II detector at the Fermilab Tevatron pp collider. Assuming CP conservation, a good approximation for the B 0 s system in the standard model, we obtain AF = 0.076 +0.059 -0.063 ± 0.006(syst) ps -1 and τ = 1.52 ± 0.04(stat) ± 0.02(syst) ps, the most precise measurements to date. Our constraints on the weak phase and AF are consistent with CP conservation.