THE KUGO-OJIMA CONFINEMENT CRITERION AND THE INFRARED BEHAVIOUR OF LANDAU GAUGE QCD

Fizika B (Zagreb)

REINHARD ALKOFER¹  CHRISTIAN S. FISCHER¹ 

关键词: confinement;    Dyson-Schwinger equations;    dynamical chiral symmetry breaking;   

DOI  :  

学科分类：物理（综合）

来源: Fizika B: a journal of experimental and theoretical physics

【 摘 要 】

Recent investigations of the Dyson-Schwinger equations and Monte-Carlo latticecalculations resulted in a coherent description of the fully dressed gluon, ghost andquark propagators in Landau gauge QCD. In the Dyson-Schwinger approach, the infraredbehaviour of these propagators is determined analytically. For finite spacelike momentathe gluon, ghost and quark propagators are compared to available corresponding results oflattice Monte-Carlo calculations. For all three propagators, an almost quantitativeagreement is found. These results for the non-perturbative propagators allow an analyticalverification of the Kugo-Ojima confinement criterion. Our numerical analysis clearlyreveals positivity violation for the gluon propagator generated by a cut in the complexmomentum plane. The non-perturbative strong running coupling resulting from thesepropagators possesses an infrared fixed point. The quark propagator obtained from quenchedand unquenched calculations displays dynamical chiral symmetry breaking with quark massesclose to "phenomenological" and lattice values. We confirm that linearextrapolations of the quark propagator for different bare masses to the chiral limit areinaccurate.

【 授权许可】

Unknown