Charged Multiplicity of Hadronic Events Containing Heavy-Quark Jets

Abstract

The charged-particle multiplicities of hadronic events deriving from produced bottom or charm quarks have been measured in the Mark II detector at PEP in ${e}^{+}{e}^{\ensuremath{-}}$ annihilation at 29 GeV. For events containing one semileptonic and one hadronic weak decay, we find multiplicities of 15.2\ifmmode\pm\else\textpm\fi{}0.5\ifmmode\pm\else\textpm\fi{}0.7 for bottom and 13.0\ifmmode\pm\else\textpm\fi{}0.5\ifmmode\pm\else\textpm\fi{}0.8 for charm. The corresponding multiplicities of charged particles accompanying the pair of heavy hadrons are 5.2\ifmmode\pm\else\textpm\fi{}0.5\ifmmode\pm\else\textpm\fi{}0.9 for bottom, and 8.1\ifmmode\pm\else\textpm\fi{}0.5\ifmmode\pm\else\textpm\fi{}0.9 for charm.