P. Abreu et al., MEASUREMENT OF THE B0-(B0)OVER-BAR MIXING USING THE AVERAGE ELECTRIC CHARGE OF HADRON-JETS IN Z0-DECAYS, Physics letters. Section B, 322(4), 1994, pp. 459-472
From the data recorded with the DELPHI detector at LEP in the years 19
91-1992, 46 497 events were selected having a high-momentum muon in ha
dron jets. A fit to the average electric charge sum of the jets recoil
ing against a b-quark jet tagged by a high-PT muon results in an avera
ge mixing parameter of chiBAR = 0.144 +/- 0.014(stat.)+0.017/-0.011(sy
st.).