2018 Impact factor 4.843
Particles and Fields
Eur. Phys. J. C 16, 41-60
DOI 10.1007/s100520000387

Measurements of Rb, AFBb, and AFBc
in ${\rm e^+ e^-}$ collisions at 130 - 189 GeV

The OPAL Collaboration

G. Abbiendi$^{\rm 2}$ - et al.

$^{\rm 2}$ Dipartimento di Fisica dell' Università di Bologna and INFN, 40126 Bologna, Italy

Received: 29 November 1999 / Published online: 8 May 2000 - © Springer-Verlag 2000

Abstract
The cross-section ratio $R_{\mathrm{b}} = \sigma( \rm e^+ e^- \to {\rm b\overline{\rm b}} )/\sigma(\rm e^+ e^- \to {\mathrm q\bar{\mathrm q}} )$and the bottom and charm forward-backward asymmetries AFBb and AFBcare measured using event samples collected by the OPAL detector at centre-of-mass energies between 130 and 189 GeV. Events with bottom quark production are selected with a secondary vertex tag, and a hemisphere charge algorithm is used to extract AFBb. In addition, the bottom and charm asymmetries are measured using leptons from semileptonic decays of heavy hadrons and pions from $\mathrm{D}^{*+}\to\rm D^0{\pi^+}$ decays. The results are in agreement with the Standard Model predictions.


Copyright Società Italiana di Fisica, Springer-Verlag 2000