The Schroedinger functional coupling in quenched QCD at low energies

TL;DR

This paper extends non-perturbative calculations of the Schroedinger functional coupling in quenched QCD to lower energies, revealing deviations from perturbative predictions at scales around 0.9 fm.

Contribution

It provides the first non-perturbative results of the coupling at such low energies in quenched QCD using the Schroedinger functional scheme.

Findings

Significant deviation from perturbative evolution at 1/mu ~ 0.9 fm

Extended the energy scale range of non-perturbative coupling computations

Demonstrated the importance of non-perturbative effects at low energies

Abstract

Existing non-perturbative computations of the running coupling of quenched QCD in the Schroedinger functional scheme are extended to scales mu lying much deeper in the low-energy regime. We are able to reach 1/mu ~ 0.9 fm, where a significant deviation from its perturbative evolution is observed.