B-lifetime measurements at CDF

The average b-hadron lifetime has been measured using a high statistics sample of B → J/ψX decays recorded with the Collider Detector at Fermilab. The decay vertices of J/ψ → μ+μ- candidates have been reconstructed using information from a silicon vertex-detector. The measured B lifetime, which is the average over all b-hadrons produced in p bar p collisions at √s = 1.8 TeV, weighted by their branching ratios into J/ψ is: τB = 1.46 ± 0.06(stat.) ± 0.06(sys.)ps (preliminary); In addition we used the fully reconstructed final states B± → J/ψK± and B0 → J/ψK0* to measure the exclusive lifetime of charged and neutral B-mesons. We measure: τB± = 1.59 ± 0.27(stat.) ± 0.17(sys.) ps (preliminary); τB0 = 1. 34 ± 0.31 (stat.) ± 0.17 (sys.) ps (preliminary); From this we obtain the following result for the lifetime ratio: τB±/τ B0 = 1.19 ± 0.35(stat.) ± 0.12(sys.) (preliminary); This represents the first measurements of the b-lifetime at a hadron collider