Related papers: The mass gap and gluon confinement
The massive screened expansion for pure SU(3) Yang-Mills theory is extended to finite temperature in the Landau gauge. All thermal integrals are evaluated analytically up to an external one-dimensional integration, yielding explicit…
We solve numerically the Schwinger-Dyson (SD hereafter) ghost equation in the Landau gauge for a given gluon propagator finite at k=0 (alpha_gluon=1) and with the usual assumption of constancy of the ghost-gluon vertex ; we show that there…
We reexamine the conventional arguments concerned with the scaling and decoupling solutions for the ghost and gluon propagators in the Landau gauge Yang-Mills theory. We point out a few issues to be clarified, which seems to be overlooked…
We study in detail the impact of dynamical quarks on the gluon mass generation mechanism, in the Landau gauge, for the case of a small number of quark families. As in earlier considerations, we assume that the main bulk of the unquenching…
In order to clarify the mechanism of quark confinement in the Yang-Mills theory with mass gap, we propose to investigate the massive Yang-Mills model, namely, Yang-Mills theory with ``a gauge-invariant gluon mass term'', which is to be…
The equation for the gluon propagator in the approach of Baker-Ball-Zachariasen is considered. The possibility of non-integer power infrared behaviour is studied, $D(q) \sim (q^2)^{-c}$, $q^2 \rightarrow 0$. It is shown that the…
The infrared limit of the lattice Landau gauge gluon propagator is studied. We show that the lattice data is compatible with the pure power law $(q^2)^{2 \kappa}$ solution of the Dyson-Schwinger equations. Using various lattice volumes, the…
Two-quark--two-antiquark systems with four different quark flavors are considered in the framework of two-dimensional QCD, in the light-cone gauge, at leading orders of the $1/N_c^{}$ expansion. Introducing basis functions with…
It is shown that the solution of the quark Dyson-Schwinger equation in QCD obtained with a gluon propagator of the form $D(q) \sim q^2/[q^4+b^4]$ and a quark-gluon vertex that is free of kinematic singularities does not describe a confined…
The local composite operator A^2 is added to the Zwanziger action, which implements the restriction to the Gribov region in Euclidean Yang-Mills theories in the Landau gauge. We prove the renormalizability of this action to all orders of…
Lattice studies of the infrared behavior of gluon and ghost propagators are a key probe of confinement scenarios in Yang-Mills theories. However, finite-volume effects become an important issue as the infrared limit is approached. By…
In a functional approach to QCD the infrared behaviour of Landau gauge Green functions is investigated. It can be proven that the ghost Dyson-Schwinger equation implies the Gribov-Zwanziger horizon condition. Its relation to the Kugo-Ojima…
We propose a mechanism displaying gluon confinement, as defined by the behavior of the propagators, in a model of SU(2) gauge fields. The model originates from an explicitly broken SU(3) gauge theory giving rise to a replica model composed…
The resolution of Dyson-Schwinger equations leads to the freezing of the QCD running coupling (effective charge) in the infrared, which is best understood as a dynamical generation of a gluon mass function, giving rise to a momentum…
Massive Yang-Mills theory is known to be renormalizable in 1+1 dimensions. The gluon mass is introduced by coupling the gauge field to an SU(N) principal chiral nonlinear sigma model. The proof of renormalizability relies on the asymptotic…
The gauge invariant generation of an effective gluon mass proceeds through the well-known Schwinger mechanism, whose key dynamical ingredient is the nonperturbative formation of longitudinally coupled massless bound-state excitations. These…
The Landau gauge gluon propagator for the pure gauge theory is evaluated on a 32^3x64 lattice with a physical volume of (3.35^3x6.7)fm^4. Comparison with two smaller lattices at different lattice spacings allows an assessment of finite…
We show that the controversies on the gauge dependence and the infrared singularity emerged in the generalized factorization approach for nonleptonic heavy meson decays within the framework of the operator product expansion can be resolved…
Lattice simulations along with studies in continuum QCD indicate that non-perturbative quantum fluctuations lead to an infrared regularisation of the gluon propagator in covariant gauges in the form of an effective mass-like behaviour. In…
A closed formula is obtained for the infrared singularities of dimensionally regularized, massless gauge-theory scattering amplitudes with an arbitrary number of legs and loops. It follows from an all-order conjecture for the…