A Combination of Preliminary Electroweak Measurements and Constraints on the Standard Model

This note presents a combination of published and preliminary electroweak results from the four LEP collaborations and the SLD collaboration which were prepared for the 1997 summer conferences. Averages are derived for hadronic and leptonic cross-sections, the leptonic forwardbackward asymmetries, the polarisation asymmetries, the bb and cc partial widths and forwardbackward asymmetries and the qq charge asymmetry. The major changes with respect to results presented last year are updated results of ALR from SLD, and the inclusion of the rst direct measurements of the W mass and triple-gauge-boson couplings performed at LEP. The results are compared with precise electroweak measurements from other experiments. The parameters of the Standard Model are evaluated, rst using the combined LEP electroweak measurements, and then using the full set of electroweak results. The LEP Collaborations each take responsibility for the preliminary data of their own experiment. yD. Abbaneo, J. Alcaraz, P. Antilogus, T. Behnke, B. Bertucci, A. Blondel, C. Burgard, R. Clare, P.E.L. Clarke, S. Dutta, M. Elsing, R. Faccini, D. Fassouliotis, M.W. Gr unewald, A. Gurtu, K. Hamacher, J.B. Hansen, R.W.L. Jones, P. de Jong, T. Kawamoto, M. Kobel, E. Lan con, W. Lohmann, C. Mariotti, M. Martinez, C. Matteuzzi, M.N. Minard, K. Monig, P. Molnar, A. Nippe, S. Olshevski, Ch. Paus, M. Pepe-Altarelli, S. Petzold, B. Pietrzyk, G. Quast, D. Reid, P. Renton, J.M. Roney, R. Sekulin, R. Tenchini, F. Teubert, M.A. Thomson, J. Timmermans, M.F. Turner-Watson, H. Wahlen, C.P. Ward, D.R. Ward, N.K. Watson, A. Weber. zN. de Groot, E. Etzion, B. Schumm, D. Su.