B lifetime measurements with exclusively reconstructed B decays
  Data collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC are used to study the lifetime of the B0 and B+ mesons. The data sample consists of 7.4 fb-1 collected near the Y(4S) resonance. B0 and B+ mesons are fully reconstructed in several exclusive hadronic decay modes to charm and charmonium final states. The B lifetime are determined from the flight length difference between the two B mesons. The preliminary measurements of the lifetimes are tau_{B0} = 1.506 +/- 0.052 (stat) +/- 0.029 (syst) ps tau_{B+} = 1.602 +/- 0.049 (stat) +/- 0.035 (syst) ps and of their ratio is tau_{B+}/tau_{B0} = 1.065 +/- 0.044 (stat) +/- 0.021 (syst). 
Chih-hsiang Cheng (for the BABAR Collaboration)