Precise Measurement of the b-Quark Fragmentation Function in Z0 Boson Decays

We have developed a new technique for inclusive reconstruction of the energy of B hadrons. The excellent efficiency and resolution of this technique allow us to make the most precise determination of the b-quark fragmentation function, using e+e-→Z0 decays recorded in the SLAC Large Detector experiment. We compared our measurement with the predictions of a number of fragmentation models. We excluded several of these models and measured the average scaled energy of weakly decaying B hadrons to be (xB) = 0.714 ± 0.005(stat) ± 0.007(syst) ± 0.002 (model dependence). © 2000 The American Physical Society.