No abstract

From measurements of the cross sections for eẽ-~hadrons and the cross sections and forward-backward charge-asymmetries for e e-~e + e-,~+-and s-r at several centreof-mass energies around the Z" pole with the DELPHI apparatus, using approximately 150000 2 = 0.0003±0.0010and A~= 0.2508±1)0027. These values correspond to the electroweak parameters: PCV = 1.003±0.011and sin20~j 0.241±0.009.Within the Minimal Standard Model (MSM). the results can he expressed in terms of a single parameter: sin20~=0.2338±0.0027.All these values are in good agreement with the predictions ot the MSM. Fits yield 43< m 115, < 215 0eV at the 95Vr level. Finally, the measured values of "z and arc used to derive lower mass bounds for possible new particles. * The VD, which was operated during most of the 1990 data collection period, was used in the alignment procedure of the barrel tracking detectors, but was not used directly in the analysis described here. * Fits with the formula of ref. [26] tend to underestimate M~and T~by about 2 MeV and to overestimate a'1~by approximately 0.1%.

The correlations in rapidity in hadron production from e+e− annihilation near the Z0 resonance were studied by means of the method of factorial moments, using data taken with the DELPHI detector at LEP. The parton shower hadronization model was found to be in quantitative agreement with the data, in contrast with previous results at lower energies

We have studied the energy-energy angular correlations in hadronic final states from Z0 decay using the DELPHI detector at LEP. From a comparison with Monte Carlo calculations based on the exact second order QCD matrix element and string fragmentation we find that View the MathML source. MeV, which corresponds to αs(91 GeV)=0.106±0.003(stat.)±0.003(syst.)+0.003-0.000(theor). The theoretical error stems from different choices for the renormalization scale of αs. In the Monte Carlo simulation the scale of αs as well as the fragmentation parameters have been optimized to described reasonably well all aspects of multihadron production

We have measured the inclusive production properties of D and View the MathML source messons produced from pp interactions at View the MathML source. The differential production cross section is well represented by the empirical form View the MathML source, and the inclusive View the MathML source cross section σView the MathML source is (30.2±3.3) ωb. The QCD fusion model predicts View the MathML source production which is in good agreement with our data except for the magnitude of the cross section which depends sensitively on the assumed mass of the charm quark