Infrared exponents and the running coupling of Landau gauge QCD and their relation to confinement
Institute for Theoretical Physics, University of Tübingen, Auf der Morgenstelle 14, D-72076, Tübingen, Germany
2 Institute for Theoretical Physics III, University of Erlangen-Nürnberg, Staudtstr. 7, D-91058, Erlangen, Germany
* e-mail: Reinhard.Alkofer@uni-tuebingen.de
The infrared behaviour of the gluon and ghost propagators in Landau gauge QCD is reviewed. The Kugo-Ojima confinement criterion and the Gribov-Zwanziger horizon condition result from quite general properties of the ghost Dyson-Schwinger equation. The numerical solutions for the gluon and ghost propagators obtained from a truncated set of Dyson-Schwinger equations provide an explicit example for the anticipated infrared behaviour. The results are in good agreement with corresponding lattice data obtained recently. The resulting running-coupling approaches a fix point in the infrared, . Two different fits for the scale dependence of the running coupling are given and discussed.
© Società Italiana di Fisica and Springer-Verlag, 2003