Nonperturbative quark-gluon dynamics

Abstract

We summarize recent results on the nonperturbative quark-gluon interaction in Landau gauge QCD. Our analytical analysis of the infrared behaviour of the quark-gluon vertex reveals infrared singularities, which lead to an infrared divergent running coupling and a linear rising quark-antiquark potential when chiral symmetry is broken. In the chirally symmetric case we find an infrared fixed point of the coupling and, correspondingly, a Coulomb potential. These findings provide a new link betwen dynamical chiral symmetry breaking and confinement.

4 pages; Talk given by CF at the 11th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon (MENU07), September 10-14, 2007, Forschungzentrum Juelich, Germany