ar X iv : h ep - p h / 99 09 22 6 v 1 2 S ep 1 99 9 1 Power corrections and renormalon resummation for the average thrust ∗

Infrared power corrections for the average thrust T in e + e − annihilation are analyzed in the framework of renormalon resummation, motivated by analogy with the skeleton expansion in QED and the BLM approach. Performing the " massive gluon " renormalon integral a renormalization scheme invariant result is obtained. We find that a major part of the discrepancy between the known next-to-leading order (NLO) calculation and experiment can be explained by resummation of higher order perturbative terms. This fact does not preclude the infrared finite coupling interpretation with a substantial 1/Q power term. Fitting the regularized perturbative sum plus a 1/Q term to experimental data yields α MS s (MZ) = 0.110 ± 0.006.