Previously developed Pade-related method of resummation for QCD observables, which achieves exact renormalization-scale-invariance, is extended so that the scheme-invariance is obtained as well. The dependence on the leading scheme parameter c2is eliminated by a variant of the method of the principle of minimal sensitivity. The subleading parameter c3in the approximant is then fixed in such a way that the correct known location of the leading infrared renormalon pole is reproduced. Thus, β-functions which go beyond the last perturbatively calculated order in the observable are used. The β-functions in the approximant are quasianalytically continued by Pade approximants. Two aspects of nonperturbative physics are accounted for in the presented resummation: a mechanism of quasianalytic continuation from the weak- into the strong-coupling regime, and the (approximant-specific) contribution of the leading infrared renormalon. The case of the Bjorken polarized sum rule is considered as a specific example of how the method works. (C) 2000 Published by Elsevier Science B.V.
|Number of pages||11|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|Publication status||Published - 27 Jul 2000|