2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/179103We discuss the perturbative running of alpha_s in a model independent way. Our analysis contains data on the hadronic tau decay and hadronic cross sections in e+e- annihilation between 5 GeV and M_Z. We determine the color coefficients and the perturbative beta-function of the strong interaction. The results are in agreement with QCD and rule out the QCD+light gluino scenarios on the 70.8 - 93.0% CL. We combine our method with that of the multi-jet analysis at LEP. The combined result rules out light gluinos at least on the 99.76% CL, provided that nonperturbative effects are not large.6 pages, Latex, 3 eps figures included. Recently calculated three-loop calculations and some new experimental results are included in the analysisHigh Energy Physics - PhenomenologyHigh Energy Physics - Experimenttext