REFINED ANALYSIS OF THE ELECTROWEAK PRECISION DATA

We refine our recent analysis of the electroweak precision data at the Z(0) pole by including the hadronic decay modes of the Z(0). Within t he framework of an effective Lagrangian we parametrize SU(2) violation by the additional process-specific parameters Delta y(v), Delta y(h), and Delta y(b) (for the Z(0)v ($) over bar v, Z(0)q<($)over bar $>q, and Z(0)b<($)over bar $>b vertices) together with the previously intro duced parameters Delta x, Delta y, and epsilon. We find that a six-par ameter analysis of the experimental data is indeed feasible, and it is carried out in addition to a four-parameter fit for Delta x, Delta y, epsilon, and Delta y(b) only. We re-emphasize that the experimental d ata have become sensitive to the (combined) magnitude of the vertex co rrections at the W(+)l ($) over bar v (W(-)v<($)over bar $>l) and Z(0) l<($)over bar $>l vertices, Delta y, which is insensitive to the notio n of the Higgs mechanism but dependent on the non-Abelian, trilinear v ector-boson coupling. Full explicit analytical results for the standar d one-loop predictions for the above-mentioned parameters are given, a nd the leading two-loop top-quark effects are included. The analytic f ormulae for the analysis of the experimental data in terms of the para meters Delta x, Delta y etc. are presented in order to encourage exper imentalists to persue such an analysis by themselves with future data.