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

Abstract

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 (q2)2{kappa} of the Dyson-Schwinger equations is investigated and the exponent {kappa} is measured. Some results for the ghost propagator and for the running coupling constant will also be shown.

Authors:
;  [1]
  1. Centro de Fisica Computacional, Departamento de Fisica, Universidade de Coimbra, P-3004-516 Coimbra (Portugal)
Publication Date:
OSTI Identifier:
21056813
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 892; Journal Issue: 1; Conference: QCHS7: 7. conference on quark confinement and the hadron spectrum, Ponta Delgada, Acores (Portugal), 2-7 Sep 2006; Other Information: DOI: 10.1063/1.2714377; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ASYMMETRY; COUPLING CONSTANTS; GAUGE INVARIANCE; GLUONS; INFRARED DIVERGENCES; LATTICE FIELD THEORY; MATHEMATICAL SOLUTIONS; PROPAGATOR; SCHWINGER FUNCTIONAL EQUATIONS

Citation Formats

Silva, P. J., and Oliveira, O. Studying the infrared behaviour of gluon and ghost propagators using large asymmetric lattices. United States: N. p., 2007. Web. doi:10.1063/1.2714377.
Silva, P. J., & Oliveira, O. Studying the infrared behaviour of gluon and ghost propagators using large asymmetric lattices. United States. doi:10.1063/1.2714377.
Silva, P. J., and Oliveira, O. Tue . "Studying the infrared behaviour of gluon and ghost propagators using large asymmetric lattices". United States. doi:10.1063/1.2714377.
@article{osti_21056813,
title = {Studying the infrared behaviour of gluon and ghost propagators using large asymmetric lattices},
author = {Silva, P. J. and Oliveira, O.},
abstractNote = {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 (q2)2{kappa} of the Dyson-Schwinger equations is investigated and the exponent {kappa} is measured. Some results for the ghost propagator and for the running coupling constant will also be shown.},
doi = {10.1063/1.2714377},
journal = {AIP Conference Proceedings},
number = 1,
volume = 892,
place = {United States},
year = {Tue Feb 27 00:00:00 EST 2007},
month = {Tue Feb 27 00:00:00 EST 2007}
}
  • We present a numerical study of the lattice Landau gluon and ghost propagators in three-dimensional pure SU(2) gauge theory. Data have been obtained using asymmetric lattices (V=20{sup 2}x40, 20{sup 2}x60, 8{sup 2}x64, 8{sup 2}x140, 12{sup 2}x140, and 16{sup 2}x140) for the lattice coupling {beta}=3.4 in the scaling region. We find that the gluon (respectively, ghost) propagator is suppressed (respectively, enhanced) at small momenta in the limit of large lattice volume V. By comparing these results with data obtained using symmetric lattices (V=20{sup 2},60{sup 3},and140{sup 3}), we find that both propagators suffer from systematic effects in the infrared region (p <more » or approx. 650 MeV). In particular, the gluon (ghost) propagator is less IR suppressed (enhanced) than in the symmetric case. We discuss possible implications of the use of asymmetric lattices.« less
  • We study the Landau gauge gluon and ghost propagators of SU(3) gauge theory, employing the logarithmic definition for the lattice gluon fields and implementing the corresponding form of the Faddeev-Popov matrix. This is necessary in order to consistently compare lattice data for the bare propagators with that of higher-loop numerical stochastic perturbation theory. In this paper we provide such a comparison, and introduce what is needed for an efficient lattice study. When comparing our data for the logarithmic definition to that of the standard lattice Landau gauge we clearly see the propagators to be multiplicatively related. The data of themore » associated ghost-gluon coupling matches up almost completely. For the explored lattice spacings and sizes discretization artifacts, finite size, and Gribov-copy effects are small. At weak coupling and large momentum, the bare propagators and the ghost-gluon coupling are seen to be approached by those of higher-order numerical stochastic perturbation theory.« less
  • The infrared limit of the lattice Landau gauge gluon propagator is studied. We show that the lattice data are compatible with the pure power law (q{sup 2}){sup 2{kappa}} solution of the Dyson-Schwinger equations. Using various lattice volumes, the infinite volume limit for the exponent {kappa} is measured. Although, the results allow {kappa}=0.498-0.525, the lattice data favor {kappa}{approx}0.52, which would imply a vanishing zero momentum gluon propagator.
  • A truncation scheme for the Dyson-Schwinger equations of Euclidean QCD in Landau gauge is presented. It implements the Slavnov-Taylor identities for the three-gluon and ghost-gluon vertices, whereas irreducible four-gluon couplings as well as the gluon-ghost and ghost-ghost scattering kernels are neglected. The infrared behavior of gluon and ghost propagators is obtained analytically: The gluon propagator vanishes for small momenta, whereas the ghost propagator diverges strongly. The numerical solutions are compared with recent lattice results. The running coupling approaches a fixed point, {alpha}{sub c}{approx_equal}9.5 , in the infrared. {copyright} {ital 1997} {ital The American Physical Society}