New measurement of b-hadron lifetimes at CDF

A measurement of b-hadron lifetimes in the fully reconstructed decay modes B+ → J/Ψ K+, B0 → J/Ψ K*0, B0 → J/Ψ Ks0, and Λb0 → J/Ψ Λ0 is reported using data corresponding to an integrated luminosity of 4.3 fb-1, collected by the CDF II detector at the Fermilab Tevatron. The measured values are τ(B+) = 1.639 ± 0.009(stat) ± 0.009(syst) ps, τ(B0) = 1.507 ± 0.010(stat) ± 0.008(syst) ps and τ(Λb0) = 1.537 ± 0.045(stat) ± 0.014(syst) ps. The lifetime ratios are τ(B+)/τ(B0) = 1.088 ± 0.009(stat) ± 0.004(syst) and τ(Λb0)/τ(B0) = 1.020 ± 0.030(stat) ± 0.008(syst). These are the most precise measurements of these lifetimes and ratios.