Measurement Of The Bar B Lifetime And Of The B Bar B Oscillation Frequency Using Partially Reconstructed Bar B D L Anti Nusub L Decays PDF Download

We measure the B° lifetime [tau]{sub b°} and the B°-{bar B}° oscillation frequency [Delta]m{sub d} with a sample of approximately 14,000 exclusively reconstructed B{sup 0} 2!D*− l [nu]{sub {ell}} signal events, selected from 23 million B{bar B} pairs recorded at the [Upsilon](4S) resonance with the BABAR detector at the Stanford Linear Accelerator Center. The decay position of the other B is determined with the remaining tracks in the event, and its b-quark flavor at the time of decay is determined with a tagging algorithm that exploits the correlation between the flavor of the b-quark and the charges of its decay products. The lifetime and oscillation frequency are measured simultaneously with an unbinned maximum-likelihood ([Delta]t) that uses, for each event, the measured difference in decay times of the two B mesons ([Delta]t), the calculated uncertainty on [Delta]t, the signal and background probabilities, and b-quark tagging information for the other B. The results are [tau]{sub B{sup 0}} = (1.523{sub -0.023}{sup +0.024} ± 0.022) ps and [Delta]m{sub d} = (0.492 ± 0.018 ± 0.013) ps−1.