Tests of QCD using Heavy Flavors at SLD

We present preliminary results on three SLD analyses: the gluon energy spectrum in 3-jet bb̄g events, the rate of g → bb̄, and the b fragmentation function in Z decays. The gluon energy spectrum, measured over the full kinematic range, is compared with perturbative QCD predictions. We set new 95% C.L. limits on the anomalous chromomagnetic coupling of the b quark: −0.09 < κ < 0.06. gbb̄ is measured to be (3.07 ± 0.71 (stat) ± 0.66 (syst)) ×10. The inclusive B hadron energy distribution in Z decays is measured for the first time over the full kinematic range, using a novel B hadron energy reconstruction technique. Several models of b fragmentation including JETSET + Peterson are excluded by the data. The average scaled B hadron energy of the weakly decaying B hadron is measured to be xB = 0.713 ± 0.005 (stat) ± 0.007 (syst) ± 0.002 (model). All three measurements take advantage of the small and stable SLC interaction point as well as the excellent vertexing and tracking capabilities of the upgraded CCD-pixel vertex detector. Invited talk presented at the XXXIVth Rencontres de Moriond QCD and High Energy Hadronic Interactions Les Arcs, Savoie, France March 20-27, 1999 ∗ Work supported in part by Department of Energy contracts DE-FC02-94ER40818 and DE-AC03-76SF00515.