In 1992 the SLD experiment at SLAC collected over 11,000 hadronic decay events of Z[sup 0] bosons produced in collisions of polarised electrons with unpolarised positrons delivered by the SLC. Preliminary experimental results are presented on tests of the value of the gluon spin involving events containing three hadronic jets measured in the final state. A leading order QCD prediction is found to be in agreement with the data, whilst a model including scalar gluons is clearly excluded. Effects of the electron beam polarisation upon the orientation of the three-jet event plane are discussed.

Z[degrees] bosons have been produced by collisions of longitudinally polarized electrons with unpolarized positrons at the SLAC Linear Collider and their decays have been recorded by the SLD experiment. We present preliminary measurements of the properties of the resulting Z[degrees] decays into multi-hadronic final states. We find good agreement with the predictions of perturbative QCD and fragmentation models.

Z° bosons have been produced by collisions of longitudinally polarized electrons with unpolarized positrons at the SLAC Linear Collider and their decays have been recorded by the SLD experiment. We present preliminary measurements of the properties of the resulting Z° decays into multi-hadronic final states. We find good agreement with the predictions of perturbative QCD and fragmentation models.

The authors have measured the production rates as a function of scaled energy x of prompt charmed pseudoscalar D[sup[+-]] and vector D*[sup[+-]] mesons in hadronic Z[sup 0] decays. The prompt signal components were isolated from the background of D mesons from B hadron decays using impact parameters of reconstructed D[sup[+-]][yields] K[sup[minus-plus]][pi][sup[+-]][pi][sup[+-]] and D*-daughter D[sup 0][yields] K[sup[minus]][pi][sup+] and D[sup 0][yields] K[sup[minus]][pi][sup+][pi][sup[minus]][pi][sup+] candidates. Using the combined meson production rates the authors have measured the fraction of hadronic Z[sup 0] decays into c[bar c], R[sub c]= 0.182[+-] 0.027 (stat.)[+-] 0.012 (syst.) (Preliminary). Comparison of the D*[sup[+-]] and D[sup[+-]] rates gives a direct probe of vector (V) vs. pseudoscalar (P) meson production for charmed quarks, and for x> 0.4 they have measured P[sub V]= V/(V+ P)= 0.65[+-] 0.09(stat.)[+-] 0.03(syst.)[+-] 0.03 (BR) (Preliminary). They have measured the degree of spin alignment of the D*[sup[+-]] mesons along their flight direction and find it to be consistent with zero. They compared the latter two results with QCD- and model-based predictions of charm-quark jet fragmentation.

We have measured production of?{sup {+-}},?{sup {+-}}, {ital p}/{ital {bar p}},?° and?°/{bar?}° as a function of momentum in inclusive hadronic {ital Z}° decay events and separately in events containing primary light-({ital uds}) and {ital b}-quarks. The SLD Cherenkov Ring Imaging Detector was used to identify charged pions, kaons, and protons over most of the available momentum range 0.8>{ital p}>33 GeV/c. The neutral?°{sub s} and {Lambda}° were reconstructed using the??− and {ital p}?− decay modes, respectively. We present the first comparisons of momentum of charged tracks measured in the SLD Vertex Detector. Substantial differences are observed, consistent with the kinematics of {ital B}-hadron production in Z° decays and the properties of {ital B}-hadron decays as measured at lower energies.