Conformal coefficients, renormalons and power corrections - the average thrust as a case study

by E. GARDI (Ecole Polytechnique, Palaiseau)

Friday 3 Dec 1999, 14:00 → 14:15 Europe/Zurich

TH Auditorium (CERN)

Assuming an Abelian-like dressed skeleton expansion, running coupling effects (renormalons) can be resummed in a renormalization-group invariant way. The coefficients of the 'skeleton expansion' are identified as conformal coefficients, defined in the presence of a perturbative infrared fixed-point. Renormalon resummation and the associated power corrections at the single dressed gluon approximation are studied in the case of the average thrust in e⁺e^- annihilation. It is found that running coupling effects lead to significant higher order perturbative corrections, closing most of the gap between the NLO QCD result and experiment. We extract from the data aSUB>s = 0.110 ± 0.002.