A measurement of the forward-backward asymmetries of e+e-→Z0→bb and e+e-->Z°→cc̄ using electrons and muons produced in semileptonic decays of bottom and charm hadrons is presented. Two new variables designed to optimize flavour separation are used in a maximum likelihood fit to a sample of events containing one or two identified leptons, allowing the simultaneous extraction of the b and c quark forward-backward asymmetries as well as the average B°-B° mixing. Using all data collected by OPAL up to the end of 1994, the asymmetries are measured to be: AFB b = ( 5.5±2.4 ±0.3 )% AFB b = (-7.5±3.4 ±0.6 )% at (√s) = 89.52 GeV, AFB b = (9.06±0.51±0.23)% AFB b= ( 6.00±0.67±0.52)7c at (√s) = 91.24 GeV, AFB b =(11.7±2.0 ±0.3 )% AFB b =( 14.l±2.8 ±0.9 )% at (√s) = 92.94 GeV. For the average B°-B° mixing a value of: X = 0.1107 ±0.0062 ±0.0055, is obtained, where in each case the first error is statistical and the second systematic.
|Number of pages||13|
|Journal||Zeitschrift fur Physik C-Particles and Fields|
|Publication status||Published - 1996|
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)