Two particle angular correlations in e+ e- interactions compared with QCD predictions

Two--particle angular correlations in jet cones have been measured in $e^+e^-$ annihilation into hadrons at LEP energies ($\sqrt{s}=$ 91 and 183~GeV) and are compared with QCD predictions using the LPHD hypothesis. Two different functions have been tested. While the differentially normalized correlation function shows substantial deviations from the predictions, a globally normalized correlation function agrees well. The size of $\alpha_S^{\rm eff}$ (and other QCD parameters) and its running with the relevant angular scale, the validity of LPHD, and problems due to non--perturbative effects are discussed critically

Identified particles in quark and gluon jets

A sample of about 1.4 million hadronic Z decays, selected among the data recorded by the DELPHI detector at LEP during 1994, was used to measure for the first time the momentum spectra of K+, K0, p, Λ and their antiparticles in gluon and quark jets. As observed for inclusive charged particles, the production spectra of identified particles were found to be softer in gluon jets than in quark jets, with a higher total multiplicity