B0B̄0 oscillations at LEP

We report the LEP results on B0−B0 oscillations, together with a review of the analysis strategies. Many measurements of the Bd0 oscillation frequency have been performed giving an average, Δmd=0.486±0.015 ps−1. Lower limits on Δms are presented, giving a LEP-combined limit, Δms>11.8 ps−1, with an expected exclusion limit of 14.5 ps−1. When combined with SLD and CDF, a tantalising 2.2 σ effect at about 17 ps−1 is observed, having a probability of about 2.5% for a fluctuation of a sample where the true frequency is beyond the global sensitivity.