Lattice Landau gauge gluon propagator: Lattice spacing and volume dependence

Abstract

The interplay between the finite volume and finite lattice spacing is investigated using lattice QCD simulations to compute the Landau gauge gluon propagator. Comparing several ensembles with different lattice spacings and physical volumes, we conclude that the dominant effects, in the infrared region, are associated with the use of a finite lattice spacing. The simulations show that decreasing the lattice spacing, while keeping the same physical volume, leads to an enhancement of the infrared gluon propagator. In this sense, the data from β = 5.7 simulations, which uses an a ≈ 0.18 fm, provides a lower bound for the infinite volume propagator. * Electronic address: orlando@teor.fis.uc.pt † Electronic address: psilva@teor.fis.uc.pt

A non-perturbative study of matter field propagators in Euclidean Yang–Mills theory in linear covariant, Curci–Ferrari and maximal Abelian gauges

“…The ghost propagator, however, is not enhanced anymore in the strong coupling and, for k ≈ 0, it behaves as 1/k 2 . Such behavior of the gluon and ghost propagator is in very good agreement with the most recent lattice simulations in the Landau gauge, see [17,20,[40][41][42][43]. An interesting property of the refinement of the GribovZwanziger action is that its occurrence depends on the spacetime dimension d. In particular, for d = 3, 4, the formation of dimension-two condensates is dynamically favored and the Gribov-Zwanziger action is naturally refined [37,44].…”

Exciting flavored bound states

“…Our motivation is to verify whether a fully consistent, simultaneous numerical solution of the heavy-quark DSE and heavy-light pseudoscalar meson BSE can be obtained with a modern approach to the rainbow-ladder (RL) truncation based on the interaction proposed by Qin et al [41]. This Ansatz produces an infrared behavior of the interaction, commonly described by a "dressing function" G(k 2 ) [32], congruent with the decoupling solution found in DSE and lattice studies of the gluon propagator [7][8][9][10][11][12][13][14][15][16][17]21]. Indeed, the gluon propagator is found to be a bounded and regular function of spacelike momenta with a maximum value at k 2 = 0.…”

Spectral densities from the lattice

“…where for D(t) we use lattice data in momentum space for the gluon propagator computed in a 80 4 volume, with β = 6.0 [3]. In a loose way of speaking, we search for a solution to the integral eq.…”

“…While the simulations have been performed using volumes as large as (27 fm) 4 for the SU(2) gauge group [1] and (17 fm) 4 for the SU(3) gauge group [2], the lattice spacing used in the simulations was quite big, being 0.22 fm for SU (2) and 0.18 fm for SU (3). In a recent paper [3] by some of us, numerical evidence has been given that a large lattice spacing also changes the propagator in the infrared region. Gluons are not physical particles.…”