Eur. Phys. J. C 21, 399-410 (2001)
Measurement of using b hadron semileptonic decayThe OPAL Collaboration G. Abbiendi and et al.
Dipartimento di Fisica dell' Università di Bologna and INFN, 40126 Bologna, Italy
(Received: 26 June 2001 / Published online: 31 August 2001 -© Springer-Verlag / Società Italiana di Fisica 2001 )
The magnitude of the CKM matrix element is determined by measuring the inclusive charmless semileptonic branching fraction of beauty hadrons at OPAL based on event topology and kinematics. This analysis uses OPAL data collected between 1991 and 1995, which correspond to about four million hadronic Z decays. We measure Br( ) to be (1.63 0.53 +0.55-0.62) 10-3. The first uncertainty is the statistical error and the second is the systematic error. From this analysis, is determined to be:
The last error represents the theoretical uncertainties related to the extraction of from Br( ) using the Heavy Quark Expansion.
© Società Italiana di Fisica, Springer-Verlag 2001