UC Berkeley

Using an impact-parameter tag to select an enriched sample of Z0→bb¯ events, we have measured the difference between the average charged multiplicity of bb¯ 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→bb¯ 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 〈xE〉b=0.62±0.10±0.04.