Exponentially Modified QCD Coupling

TL;DR

This paper introduces a class of infrared-finite analytic QCD couplings that closely match perturbative QCD at high energies, with minimal scheme dependence, aiming to extend QCD applicability at low energies.

Contribution

It proposes a new phenomenological model for an analytic QCD coupling with three parameters, reducing scheme dependence and aligning with the Operator Product Expansion philosophy.

Findings

Coupling differs from perturbative QCD by less than any inverse power at high energies.

Model exhibits low loop-level and scheme dependence in the intermediate energy region.

Provides a phenomenological framework to extend QCD applicability to low energies.

Abstract

We present a specific class of models for an infrared-finite analytic QCD coupling, such that at large space-like energy scales the coupling differs from the perturbative one by less than any inverse power of the energy scale. This condition is motivated by the ITEP Operator Product Expansion philosophy. Allowed by the ambiguity in the analytization of the perturbative coupling, the proposed class of couplings has three parameters. In the intermediate energy region, the proposed coupling has low loop-level and renormalization scheme dependence. The present modification of perturbative QCD must be considered as a phenomenological attempt, with the aim of enlarging the applicability range of the theory of the strong interactions at low energies.