New Model for the QCD Analytic Running Coupling

Abstract

As an elaboration of the analytic approach to Quantum Chromodynamics (QCD), a new model for the QCD analytic running coupling is proposed. A self-evident advantage of the new analytic running coupling (NARC) is that it incorporates the infrared enhancement and the ultraviolet asymptotic freedom in a single expression. It is essential that additional parameters are not introduced in the theory. The absence of unphysical singularities in the physical region $q^2>0$ and a fairly well loop and scheme stability are the remarkable features of the NARC. By making use of practically the same values of $\Lambda_{QCD}$ in the approach developed, one succeeded in description of various physical phenomena, from quark confinement to the $\tau$ lepton decay. This undoubtedly implies that the new analytic running coupling substantially involves both the nonperturbative and the perturbative behavior of Quantum Chromodynamics.