Leipzig 2002 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
T: Teilchenphysik
T 203: QCD II
T 203.2: Vortrag
Montag, 18. März 2002, 16:30–16:45, HS 10
Confinement in Non-Perturbative Landau Gauge QCD — •Lorenz von Smekal1, Reinhard Alkofer2, Jan Martin Pawlowski1, and Daniel Zwanziger3 — 1Universität Erlangen-Nürnberg — 2Universität Tübingen — 3New York University
The conditions for confinement in the covariant continuum formulation are summarized in the Kugo-Ojima criterion. They express the necessity of a mass gap and that global gauge symmetry must be unbroken to establish the equivalence of physical states and color singlets in QCD.
Non-perturbatively, however, proper care must be taken of gauge-fixing ambiguities, i.e., the occurrence of Gribov copies. In stochastic quantization the Gribov problem is by-passed with the introduction of a globally restoring No-dqdrift forceNo-dq that generates harmless gauge transformations. The time-independent diffusion equation of this formulation is closely related to the Dyson-Schwinger equations.
In Landau gauge, neglecting a non-conservative part of the drift force, the standard equations are recovered supplemented by conditions to restrict the configuration space to the first Gribov region. These conditions imply the Kugo-Ojima criterion. Previous studies of critical infrared exponents for gluon and ghost correlations are supported. Moreover, providing for a correct counting of gauge copies inside the Gribov region, the full stochastic equation allows to compare the results to Monte-Carlo simulations with lattice implementations of the Landau gauge.