MASS CORRECTIONS TO THE TAU-DECAY RATE

In this note radiative corrections to the total hadronic decay rate of the tau-lepton are studied employing perturbative QCD and the operato r product expansion. We calculate quadratic quark mass corrections to the decay rate ration R(tau) to the order O(alpha(s)m2) and find that they contribute appreciably to the Cabbibo supressed decay modes of th e tau-lepton. We also discuss corrections of mass dimension D=4, where we emphasize the need of a suitable choice of the renormalization sca le of the quark and gluon condensates.