Measurements of Lifetimes, Mixing and CP Violation of B Mesons with the BaBar Detector

Abstract

Using a data sample of 62 million \FourS\to B\Bbar decays collected between 1999 and 2001 by the BaBar detector at the PEP2 asymmetric-energy B Factory at SLAC we study events in which one neutral B meson is fully reconstructed in a final state containing a charmonium meson and the flavour of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the Standard Model is proportional to sin(2 beta), is derived from the decay time distributions. We measure sin(2 beta) = 0.75 \pm 0.09 (stat) \pm 0.04 (syst) and |λ| = 0.92 \pm 0.06 (stat) \pm 0.02 (syst). The latter is consistent with the Standard Model expectation of no direct CP violation. These results are preliminary. In addition, we report on precision measurements of the B lifetimes, and the \Bz-\Bzb oscillation frequency \deltamd.