Infrared gluon propagator from lattice QCD: Results from large asymmetric lattices (original) (raw)

The lattice infrared Landau gauge gluon propagator: the infinite volume limit

Proceedings of The XXVII International Symposium on Lattice Field Theory — PoS(LAT2009), 2010

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 decoupling-like or the scaling-like solution of the Dyson-Schwinger equations. Furthermore, the analysis of the Cucchieri-Mendes bounds is performed considering large volume simulations and the Oliveira-Silva ratios are computed. If the first do not give a clear answer about the value of D(0), the second method favors a D(0) = 0. Finally, the SU(3) and SU(2) propagators are compared in the infrared. It comes out that the propagators are different although the infrared exponents seem to be similar. The analysis suggests a scaling behaviour D(0) ∼ N with the gauge group SU(N).

Infrared gluon and ghost propagators from lattice QCD

The European Physical Journal A, 2007

We report on the infrared limit of the quenched lattice Landau gauge gluon and ghost propagators as well as the strong coupling constant computed from large asymmetric lattices. The infrared lattice propagators are compared with the pure power law solutions from Dyson-Schwinger equations (DSE). For the gluon propagator, the lattice data is compatible with the DSE solution. The preferred measured gluon exponent being ∼ 0.52, favouring a vanishing propagator at zero momentum. The lattice ghost propagator shows finite volume effects and, for the volumes considered, the propagator does not follow a pure power law. Furthermore, the strong coupling constant is computed and its infrared behaviour investigated.

Exploring the infrared Landau gauge propagators using large asymmetric lattices

Proceedings of XXIVth International Symposium on Lattice Field Theory — PoS(LAT2006)

We report on the infrared limit of the quenched lattice Landau gauge gluon and ghost propagators computed from large asymmetric lattices. In particular, the compatibility of the pure power law infrared solutions of the Dyson-Schwinger equations with the lattice data is investigated and the exponent κ is measured. The gluon lattice data favour κ ∼ 0.52, which would imply a vanishing zero momentum gluon propagator. For the subset of lattices where the ghost propagator was computed, the data are not compatible with a pure power law. Our data also show a decreasing running coupling in the infrared region. Furthermore, positivity violation for the gluon propagator is also verified.

Towards the continuum limit of the lattice Landau gauge gluon propagator

AIP Conference Proceedings, 2011

The infrared behaviour of the lattice Landau gauge gluon propagator is discussed, combining results from simulations with different volumes and lattice spacings. In particular, the Cucchieri-Mendes bounds are computed and their implications for D(0) discussed.

Infrared gluon and ghost propagator exponents from lattice QCD

The European Physical Journal C, 2009

The compatibility of the pure power law infrared solution of QCD and lattice data for the gluon and ghost propagators in Landau gauge is discussed. For the gluon propagator, the lattice data is well described by a pure power law with an infrared exponent κ ∼ 0.53, in the Dyson-Schwinger notation. κ is measured using a technique that suppresses finite volume effects. This value implies a vanishing zero momentum gluon propagator, in agreement with the Gribov-Zwanziger confinement scenario. For the ghost propagator, the lattice data seem not to follow a pure power law, at least for the range of momenta accessed in our simulation.

1 What Lattice QCD tell us about the Landau Gauge Infrared Propagators

2010

The calculation of the Landau gauge gluon propagator performed in Coimbra using lattice QCD simulations is reviewed. Particular attention is given to the behavior of the gluon propagator in the infrared region and the value of D(0). In the second part of the article, the modeling of the lattice data using massive type propagators and Gribov type propagators is discussed. Four different mass scales are required to describe the propagator over the full range of momenta accessed by the simulations discussed here. Furthermore, assuming a momentum dependent gluon mass, we sketch on its functional dependence. The many faces of QCD November 2-5, 2010 Gent Belgium * Speaker.

What Lattice QCD tell us about the Landau Gauge Infrared Propagators

Proceedings of The many faces of QCD — PoS(FacesQCD)

The calculation of the Landau gauge gluon propagator performed in Coimbra using lattice QCD simulations is reviewed. Particular attention is given to the behavior of the gluon propagator in the infrared region and the value of D(0). In the second part of the article, the modeling of the lattice data using massive type propagators and Gribov type propagators is discussed. Four different mass scales are required to describe the propagator over the full range of momenta accessed by the simulations discussed here. Furthermore, assuming a momentum dependent gluon mass, we sketch on its functional dependence.

Lattice gauge theory studies of the gluon propagator

The gluon propagator in Landau gauge is calculated in quenched QCD on a large (32 3 × 64) lattice at β = 6.0. In order to assess finite volume and finite lattice spacing artefacts, we also calculate the propagator on a smaller volume for two different values of the lattice spacing. New structure seen in the infrared region survives conservative cuts to the lattice data, and serves to exclude a number of models that have appeared in the literature.

Studying the infrared behaviour of gluon and ghost propagators using large asymmetric lattices

AIP Conference Proceedings, 2007

We report on the infrared limit of the quenched lattice Landau gauge gluon propagator computed from large asymmetric lattices. In particular, the compatibility of the pure power law infrared solution (q 2) 2κ of the Dyson-Schwinger equations is investigated and the exponent κ is measured. Some results for the ghost propagator and for the running coupling constant will also be shown.

Exploring the infrared gluon and ghost propagators using large asymmetric lattices

Brazilian Journal of Physics, 2007

We report on the infrared limit of the quenched lattice Landau gauge gluon propagator computed from large asymmetric lattices. In particular, the compatibility of the pure power law infrared solution (q 2) 2κ of the Dyson-Schwinger equations is investigated and the exponent κ is measured. The lattice data favours κ ∼ 0.52, which would imply a vanishing zero momentum gluon propagator as predicted by the Kugo-Ojima confinement mechanism and the Zwanziger horizon condition. Results for the ghost propagator and for the running coupling constant are shown.