Towards the continuum limit of the lattice Landau gauge gluon propagator (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 behavior of the gluon propagator on a large volume lattice

Physical Review D, 2000

The first calculation of the gluon propagator using an O(a 2 ) improved action with the corresponding O(a 2 ) improved Landau gauge fixing condition is presented. The gluon propagator obtained from the improved action and improved Landau gauge condition is compared with earlier unimproved results on similar physical lattice volumes of 3.2 3 × 6.4 fm 4 . We find agreement between the improved propagator calculated on a coarse lattice with lattice spacing a = 0.35 fm and the unimproved propagator calculated on a fine lattice with spacing a = 0.10 fm. This motivates us to calculate the gluon propagator on a coarse large-volume lattice 5.6 3 × 11.2 fm 4 . The infrared behavior of previous studies is confirmed in this work. The gluon propagator is enhanced at intermediate momenta and suppressed at infrared momenta. Therefore the observed infrared suppression of the Landau gauge gluon propagator is not a finite volume effect.

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.

Infrared gluon propagator from lattice QCD: Results from large asymmetric lattices

Physical Review D, 2006

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) 2κ solution of the Dyson-Schwinger equations. Using various lattice volumes, the infinite volume limit for the exponent κ is measured. Although, the results allow κ = 0.498 − 0.525, the lattice data favours κ ∼ 0.52, which would imply a vanishing zero momentum gluon propagator.

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.

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.

Infinite volume and continuum limits of the Landau-gauge gluon propagator

Physical Review D, 2001

We extend a previous improved action study of the Landau gauge gluon propagator, by using a variety of lattices with spacings from a = 0.17 to 0.41 fm, to more fully explore finite volume and discretization effects. We also extend a previously used technique for minimizing lattice artifacts, the appropriate choice of momentum variable or "kinematic correction", by considering it more generally as a "tree-level correction". We demonstrate that by using tree-level correction, determined by the tree-level behavior of the action being considered, it is possible to obtain scaling behavior over a very wide range of momenta and lattice spacings. This makes it possible to explore the infinite volume and continuum limits of the Landau-gauge gluon propagator.