We are also grateful to the technical and engineering sta s in our laboratories and we acknowledge the support of Austrian Federal Ministry of Science, Research and Arts, FNRS-FWO, Belgium, FINEP, CNPq, CAPES, FUJB and FAPERJ, Brazil, Czech Ministry of Industry and Trade, GA CR 202/96/0450 and GA AVCR A1010521, Danish Natural Research Council, Commission of the European Communities (DG XII), Direction des Sciences de la Matiere, CEA, France, Bundesministerium fur Bildung, Wissenschaft, Forschung und Technologie, Germany, General Secretariat for Research and Technology, Greece, National Science Foundation (NWO) and Foundation for Research on Matter (FOM), The Netherlands, Norwegian Research Council, State Committee for Scienti c Research, Poland, 2P03B00108, 2P03B03311 and 628/E-78-SPUB-P03-023/97, JNICT-Junta Nacional de Investigacao CientificaeTecnologica, Portugal, Vedecka grantova agentura MS SR, Slovakia, Nr. 95/5195/134, Ministry of Science and Technology of the Republic of Slovenia, CICYT, Spain, AEN96{1661 and AEN96-1681, The Swedish Natural Science Research Council, Particle Physics and Astronomy Research Council, UK, Department of Energy, USA, DE-FG02-94ER40817.

During 1993 and 1995 LEP was run at 3 energies near the Z0 peak in order to give improved measurements of the mass and width of the resonance. During 1994, LEP operated only at the Z0 peak. In total DELPHI accumulated data corresponding to an integrated luminosity of approximately 116 pb-1. Analyses of the hadronic cross-sections and of the cross-sections and forward-backward asymmetries in the leptonic channels used the most precise evaluations of the LEP energies. In the dimuon channel, events with a photon radiated from the initial state have been used to probe the cross-sections and asymmetries down to PETRA energies. Model independent fits to all DELPHI lineshape and asymmetry data from 1990 to 1995 have been carried out giving values of the resonance parameters: MZ = 91:1863 0:0028 GeV Z = 2:4876 0:0041 GeV 0 = 41:578 0:069 nb Rl = 20:730 0:060 A0 FB = 0:0187 0:0019: These values are signi cantly more precise than those previously published. The results are interpreted in terms of the Standard Model.

DELPHI Collaboration: et al.

CERN-EP-2000-037

Peer reviewed