The Infrared Behavior of Gluon and Ghost Propagators in Landau Gauge QCD
نویسندگان
چکیده
A solvable systematic truncation scheme for the Dyson–Schwinger equations of Euclidean QCD in Landau gauge is presented. It implements the Slavnov–Taylor identities for the three–gluon and ghost–gluon vertices, whereas irreducible four–gluon couplings as well as the gluon–ghost and ghost–ghost scattering kernels are neglected. The infrared behavior of gluon and ghost propagators is obtained analytically: The gluon propagator vanishes for small spacelike momenta whereas the ghost propagator diverges more strongly than a massless particle pole. The numerical solutions are compared with recent lattice data for these propagators. The running coupling of the renormalization scheme approaches a fixed point, αc ' 9.5, in the infrared.
منابع مشابه
Infrared behavior and fixed points in Landau-gauge QCD.
We investigate the infrared behavior of gluon and ghost propagators in Landau-gauge QCD by means of an exact renormalization group equation. We explain how, in general, the infrared momentum structure of Green functions can be extracted within this approach. An optimization procedure is devised to remove residual regulator dependences. In Landau-gauge QCD this framework is used to determine the...
متن کاملKugo – Ojima Confinement Criterion , Zwanziger – Gribov Horizon Condition , and Infrared Critical Exponents in Landau Gauge Qcd
The Kugo–Ojima confinement criterion and its relation to the infrared behaviour of the gluon and ghost propagators in Landau gauge QCD are reviewed. The realization of this confinement criterion (which in Landau gauge relates to Zwanziger's horizon condition) results from quite general properties of the ghost Dyson– Schwinger equation. The numerical solutions for the gluon and ghost propagators...
متن کاملA dynamical gluon mass solution in a coupled system of the Schwinger-Dyson equations
We study numerically the Schwinger-Dyson equations for the coupled system of gluon and ghost propagators in the Landau gauge and in the case of pure gauge QCD. We show that a dynamical mass for the gluon propagator arises as a solution while the ghost propagator develops an enhanced behavior in the infrared regime of QCD. Simple analytical expressions are proposed for the propagators, and the m...
متن کاملInfrared behaviour and fixed points in Landau gauge QCD
We investigate the infrared behaviour of gluon and ghost propagators in Landau gauge QCD by means of an exact renormalisation group equation. We explain how, in general, the infrared momentum structure of Green functions can be extracted within this approach. An optimisation procedure is devised to remove residual regulator dependences. In Landau gauge QCD this framework is used to determine th...
متن کاملThe Kugo – Ojima confinement criterion and the Infrared Behavior of Landau gauge QCD ∗
Recent investigations of the Dyson–Schwinger equations and Monte– Carlo lattice calculations resulted in a coherent description of the fully dressed gluon, ghost and quark propagators in Landau gauge QCD. In the Dyson–Schwinger approach the infrared behaviour of these propagators is determined analytically. For finite spacelike momenta the gluon, ghost and quark propagators are compared to avai...
متن کامل