| Abstract: | This paper reports a study of B meson oscillations using hadronic Z0 decays with two identified leptons, and updates a previous publication by including data collected in 1994. Decay times are reconstructed for each of the semileptonic B decays by forming vertices which include the lepton and by estimating the B meson momentum. The mass difference, Δm d, between the two mass eigenstates in the B0d system is measured to be 0.430 ± 0.043 +0.028 ?0.030 ps.1, where the first error is statistical and the second error is systematic. For the B0 s system, a lower limit of Δms < 2.2 ps.1 is obtained at 95% C.L. |
