Eur. Phys. J. A (2011) 47: 49
https://doi.org/10.1140/epja/i2011-11049-8

Regular Article - Theoretical Physics

Non-perturbative momentum dependence of the coupling constant and hadronic models

¹ INFN, Sezione di Pavia, Via Bassi 6, 27100, Pavia, Italy
² Dipartimento di Fisica, Università degli Studi di Perugia, and INFN, Sezione di Perugia, via A. Pascoli, 06100, Perugia, Italy
³ Departamento de Fısica Teórica and Instituto de Fısica Corpuscular, Universidad de Valencia-CSIC, E-46100, Burjassot (Valencia), Spain

^* e-mail: Vicente.Vento@uv.es

Received: 18 February 2011
Accepted: 7 March 2011
Published online: 5 April 2011

Abstract

Models of hadron structure are associated with a hadronic scale which allows by perturbative evolution to calculate observables in the deep inelastic region. The resolution of Dyson-Schwinger equations leads to the freezing of the QCD running coupling (effective charge) in the infrared, which is best understood as a dynamical generation of a gluon mass function, giving rise to a momentum dependence which is free from infrared divergences. We use this new development to understand why perturbative treatments are working reasonably well despite the smallness of the hadronic scale.