Infrared exponents of Yang-Mills theory
Presenter: Christian S. Fischer
Abstract: We investigate the infrared behaviour of QCD Green’s functions in
the Dyson-Schwinger approach in both, the continuum and on a torus. In the
continuum we find an infrared divergent ghost propagator in accordance with the
Kugo-Ojima confinement criterion and the Gribov-Zwanziger scenario, whereas
the gluon propagator is weakly vanishing in the infrared. The resulting running
coupling has an infrared fixed point. Sizeable modifications of these results occur on the torus. Even for very large volumes, exceeding contemporary lattice
volumes by orders of magnitude, we find a finite gluon propagator in the infrared in agreement with recent lattice calculations. Our results suggest that an
infinite volume extrapolation of lattice data for the propagators is not sufficient
to obtain the continuum limit.
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