2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/36836A preliminary study of time dependence of B^0-anti-B^0 oscillations using dilepton events is presented. The flavor of the B meson is determined by the charge sign of the lepton. To separate signal leptons from cascade and fake leptons we have used a method which combines several discriminating variables in a neural network. The time evolution of the oscillations is studied by reconstructing the time difference between the decays of the B mesons produced by the Y(4S) decay. With an integrated luminosity of 7.7 fb-1 collected on resonance by BABAR at the PEP-II asymmetric B Factory, we measure the difference in mass of the neutral B eigenstates, Delta_mB0, to be (0.507+/-0.015+/-0.022) x 10^{12} hbar-s^{-1}.17 pages, 5 postscript figures, contributed paper to ICHEP2000High Energy Physics - Experimenttext