Abstract

In the Standard Model (SM), the Bqo - B ̅qo (q = d, s) mixing is a consequence of second order weak interactions. Starting with a B, meson produced at time t = 0, the probability to observe a Bqo (or B ̅qo) decaying at the time t can be written: L and H denote respectively the light and heavy states. The oscillation period gives a direct measurement of the mass difference, md between the two physical states. The time-dependent Bqo - B ̅qo oscillations have been measured from the distributions of high pt lepton impact parameter gives: