Measurement of the B0-B-0 oscillation frequency with inclusive dilepton events.

The B0-B-0 oscillation frequency has been measured with a sample of 23 x 10(6) BB- pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives deltamd = 0.493+/-0.012(stat)+/-0.009(syst) ps-1.