Gluon mass generation in the massless bound-state formalism

Abstract

We present a detailed, all-order study of gluon mass generation within the massless bound-state formalism, which constitutes the general framework for the systematic implementation of the Schwinger mechanism in non-Abelian gauge theories. The main ingredient of this formalism is the dynamical formation of bound-states with vanishing mass, which give rise to effective vertices containing massless poles; these latter vertices, in turn, trigger the Schwinger mechanism, and allow for the gauge-invariant generation of an effective gluon mass. This particular approach has the conceptual advantage of relating the gluon mass directly to quantities that are intrinsic to the bound-state formation itself, such as the "transition amplitude" and the corresponding "bound-state wave-function". As a result, the dynamical evolution of the gluon mass is largely determined by a Bethe-Salpeter equation that controls the dynamics of the relevant wave-function, rather than the Schwinger-Dyson equation of the gluon propagator, as happens in the standard treatment. The precise structure and field-theoretic properties of the transition amplitude are scrutinized in a variety of independent ways. In particular, a parallel study within the linear covariant (Landau) gauge and the background-field method reveals that a powerful identity, known to be valid at the level of conventional Green's functions, relates also the background and quantum transition amplitudes. Despite the differences in the ingredients and terminology employed, the massless bound-state formalism is absolutely equivalent to the standard approach based on Schwinger-Dyson equations. In fact, a set of powerful relations allow one to demonstrate the exact coincidence of the integral equations governing the momentum evolution of the gluon mass in both frameworks.

47 pages, 19 figures

References in corpus (14)

• A refinement of the Gribov-Zwanziger approach in the Landau gauge: infrared propagators in harmony with the lattice results
• 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
• Constraints on the IR behavior of the gluon propagator in Yang-Mills theories
• Pinch Technique: Theory and Applications
• The Physics of Glueballs
• Non-perturbative comparison of QCD effective charges
• Scaling behavior and positivity violation of the gluon propagator in full QCD
• Gluon mass generation in the PT-BFM scheme
• Exploratory study of three-point Green's functions in Landau-gauge Yang-Mills theory
• Subcritical solution of the Yang-Mills Schroedinger equation in the Coulomb gauge
• Gauge-invariant truncation scheme for the Schwinger-Dyson equations of QCD
• A model for QCD ground state with magnetic disorder
• Positivity issues for the pinch-technique gluon propagator and their resolution