Measurement of the (B)over-bar lifetime and the B-0(B)over-bar(0) oscillation frequency using partially reconstructed (B)over-bar(0)-> D*+ l-(v)over-bar(l) decays

We present a simultaneous measurement of the (B) over bar (0) lifetime tau(B0) and B-0(B) over bar (0) oscillation frequency Delta m(d). We use a sample of about 50 000 partially reconstructed (B) over bar (0)-> D(*+)l(-)nu(l) decays identified with the BABAR detector at the PEP-II e(+)e(-) storage ring at SLAC. The flavor of the other B meson in the event is determined from the charge of another high-momentum lepton. The results are tau(B0) = (1.504 +/- 0.013(stat)(-0.013)(+0.018)(syst)) ps, Delta m(d) = (0.511 +/- 0.007(stat)(-0.006)(+0.007)(syst)) ps(-1).