Analytic Approach to Perturbative QCD and Renormalization Scheme Dependence

Abstract

We further develop the approach recently used to construct an analytic ghost-free model for the QCD running coupling based on the requirement of the $Q^2$-analyticity and apply it to the process of $e^{+}{e}^{-}$ annihilation into hadrons to study the renormalization scheme dependence of the $R(s)$ cross-section ratio. \par By transforming the relevant QCD corrections up to the three-loop level into the "analytized" form we show that the $R_{AA}(s)$ expression thus obtained is remarkably stable (as compared to the conventional perturbative approach) with respect to the renormalization scheme dependence for the whole low-energy region.

Comments: 6 pages, LaTeX with psfig.sty, PostScript figure