Related papers: Positivity violations in QCD
An introduction is given into current lattice investigations of the non-perturbative gluon and ghost propagators, in the light of the Gribov-Zwanziger and Kugo-Ojima scenarios of confinement, in the context of results obtained from the…
The Landau gauge lattice gluon propagator is discussed for different sets of lattices. Particular attention is given to its infrared properties. Our results show that the lattice propagator can be made compatible with either the…
Perturbation theory is shown to be working in the IR limit of pure SU(3) Yang-Mills theory in Landau gauge by an unconventional setting of the perturbative expansion. A dynamical mass is predicted for the gluon and the lattice data are…
Newer lattice results indicate that, in the Landau gauge at low spacelike momenta, the gluon propagator and the ghost dressing function are finite nonzero. This leads to a definition of the QCD running coupling, in a specific scheme, that…
Over the last years, lattice calculations in pure Yang-Mills gauge theory seem to have come more or less to a consensus. The ghost propagator is not enhanced and the gluon propagator is positivity violating, infrared suppressed and…
The SU(2) gluon propagator in Landau gauge is studied on the lattice. Our gauge fixing procedure employs simulated annealing and Z(2)-flips. It finds higher maxima of the gauge functional compared with those obtained with the standard…
Infrared features of gluon propagator, ghost propagator, QCD running coupling and the Kugo-Ojima parameter in lattice Landau gauge QCD are presented. The framework of PMS analysis suggests that there appear infrared, intermediate and…
We study the flavorless gluon propagator in the Landau gauge from high statistics lattice calculations. Hypercubic artifacts are efficiently eliminated by taking the $\sum p_\mu^4 \to 0$ limit. The propagator is fitted to the three-loops…
The explicit one-loop renormalizability of the gluon sector of QCD with Lorentz violation is demonstrated. The result is consistent with multiplicative renormalization as the required counter terms are consistent with a single re-scaling of…
We discuss the analytic continuation of the gluon propagator from the Euclidean region to the complex squared-momentum plane towards the Minkowski region from a viewpoint of gluon confinement. For this purpose, we investigate the massive…
We formulate a dressed perturbative expansion of QCD, where the standard diagrams are evaluated in the presence of a constant external gluon field whose magnitude is gaussian distributed. The approach is Poincar{\'e} and gauge invariant,…
In this contribution we extend our unquenched computation of the Landau gauge gluon and ghost propagators in lattice QCD at non-zero temperature. The study was aimed at providing input for investigations employing continuum functional…
The properties of the quark propagator in Landau gauge in quenched QCD are examined for the overlap quark action. The overlap quark action satisfies the Ginsparg-Wilson relation and as such provides an exact lattice realization of chiral…
The gluon and ghost propagators in Landau Gauge Yang-Mills Theory are investigated. Self-consistent solutions are obtained from their equations of motion above and below the presumed phase transition. Gluon confinement is manifest in these…
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…
On the lattice we study the gauge boson propagator of three dimensional compact QED in Landau gauge at zero and non-zero temperature. The non-perturbative effects are taken into account by the generation of a mass, by an anomalous dimension…
In the present work we discuss certain characteristic features encoded in some of the fundamental QCD Green's functions, whose origin can be traced back to the nonperturbative masslessness of the ghost field, in the Landau gauge.…
We address the problem of Gribov copies in lattice QCD. The gluon propagator is computed, in the Landau gauge, using 302 ($\beta = 5.8$) $12^4$ configurations gauge fixed to different copies. The results of the simulation shows that: i) the…
There are indications of a faith transition in QCD: The strong coupling may freeze at a sufficiently low value to make PQCD relevant even in the confining regime. The properties of PQCD at low Q^2 depend on the asymptotic field…
We have explicitly shown that QCD is the color gauge invariant theory at non-zero mass gap as well. It has been defined as the value of the regularized full gluon self-energy at some finite point. The mass gap is mainly generated by the…