Experimental evidence for the existence of orbitally excited B meson states is presented in an analysis of the Bπ and B∗π distribution of View the MathML source using Z0 decay data taken with the DELPHI detector at LEP. The mean Q-value of the decays B∗∗ → B(∗)π is measured to be 284 ± 5 (stat.) ± 15 (syst.) MeV/c2, and the Gaussian width of the signal is 79 ± 5 (stat.) ± 8 (syst.) MeV/c2. This signal can be described as a single resonance of mass m = 5732 ± 5 (stat.) ± 20 (syst.) MeV/c2 and full width Γ = 145 ± 28 MeV/c2. The observed shape is also consistent with the production of several broad and narrow states as predicted by the quark model and partly observed in the D-meson sector. The production rate of B∗∗ per b-jet is found to be 0.27 ± 0.02 (stat.) ± 0.06 (syst.)

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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

An analysis of the production of the baryon in the hadronic decays of the Z 0 is presented, based on about 993K multihadronic events collected by the DELPHI detector at LEP during 1991 and 1992. The di erential cross section of the and the correlations between and produced in the same event are compared to current models, based both on string fragmentation and on cluster decay. The predictions of the string fragmentation model are found to give satisfactory agreements with the data, clearly better than those of the cluster model.