Measurement of the charged multiplicity of events containing bottom hadrons at E_{c. m.}=91 GeV

Using an impact-parameter tag to select an enriched sample of Z0-->bbBAR events, we have measured the difference between the average charged multiplicity of bbBAR and all hadronic Z0 decays to be 2.1+/-1.8(stat)+/-0.6(syst) tracks per event. The resulting total (nonleading) charged multiplicity for Z0-->bbBAR events is 23.1(12.0)+/-1.8+/-0.6 tracks. A comparison of this nonleading multiplicity to hadronic multiplicity data in the range of 10 to 60 GeV supports the hypothesis of flavor-independent hadronic fragmentation, and yields a measurement of the average energy fraction of bottom hadrons in Z0 decays of [x(E)]b =0.62+/-0.10+/-0.04.