Vertex Sensitivity in the Schwinger-Dyson Equations of QCD

Abstract

The non-perturbative gluon and ghost propagators in Landau gauge QCD are obtained using the Schwinger-Dyson equation approach. The propagator equations are solved in Euclidean space using Landau gauge with a range of vertex inputs. Initially we solve for the ghost alone, using a model gluon input, which leads us to favour a finite ghost dressing in the non-perturbative region. In order to then solve the gluon and ghost equations simultaneously, we find that non-trivial vertices are required, particularly for the gluon propagator in the small momentum limit. We focus on the properties of a number vertices and how these differences influence the final solutions. The self-consistent solutions we obtain are all qualitatively similar and contain a masslike term in the gluon propagator dressing in agreement with related studies, supporting the long-held proposal of Cornwall.

12 pages, 8 figures. Contribution to the International Workshop on QCD Green's Functions, Confinement and Phenomenology, September 5-9 2011, Trento, Italy

References in corpus (11)

• Gluon and ghost propagators in the Landau gauge: Deriving lattice results from Schwinger-Dyson equations
• Lattice gluodynamics computation of Landau-gauge Green's functions in the deep infrared
• Interaction model for the gap equation
• Non-perturbative comparison of QCD effective charges
• Commentary on rainbow-ladder truncation for excited states and exotics
• On the massive gluon propagator, the PT-BFM scheme and the low-momentum behaviour of decoupling and scaling DSE solutions
• Massless bound-state excitations and the Schwinger mechanism in QCD
• The Coulomb gauge ghost Dyson-Schwinger equation
• On the leading OPE corrections to the ghost-gluon vertex and the Taylor theorem
• Are the Dressed Gluon and Ghost Propagators in the Landau Gauge presently determined in the confinement regime of QCD?
• The Saga of Landau-Gauge Propagators: Gathering New Ammo