  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 |\lambda| = 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.
