Measurement of Lifetime and Decay-Width Difference in Bs0→J/ψφ Decays

We measure the mean lifetime τ=2/(ΓL+ΓH) and the decay-width difference ΔΓ=ΓL-ΓH of the light and heavy mass eigenstates of the Bs0 meson, BsL0 and BsH0, in Bs0→J/ψφ 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 Bs0 system in the standard model, we obtain ΔΓ=0.076-0.063+0.059(stat)±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 ΔΓ are consistent with CP conservation