Understanding perturbative results for decays of \tau leptons into hadrons

Abstract

We review some results obtained by us and others concerning the structure of higher order perturbation series in perturbative QCD and their resummation using the renormalization group equation. We illustrate our results by a number of examples involving hadronic \tau decays and e^+ e^- annihilation.

Comments: 30 pages, 2 figures, contribution to the Festschrift published on the occasion of the 60th birthday of Dmitri Kazakov