Comparing SU(2) to SU(3) gluodynamics on large lattices (original) (raw)

The Landau gauge gluon and ghost propagators in 4D SU(3) gluodynamics in large lattice volumes

2007

We present recent results of the Landau gauge gluon and ghost propagators in SU(3) pure gauge theory at Wilson \beta=5.7 for lattice sizes up to 80^4 corresponding to physical volumes up to (13.2 fm)^4. In particular, we focus on finite-volume and Gribov copy effects. We employ a gauge fixing method that combines a simulated annealing algorithm with finalizing overrelaxation. We find the gluon propagator for the largest volumes and at q^2 ~ 0.01 GeV^2 to become flat. Although not excluded by our data, there is still no clear indication of a gluon propagator tending towards zero in the zero-momentum limit. New data for the ghost propagator are reported, too.

Landau-gauge gluon and ghost propagators in 4D SU(3) gluodynamics on large lattice volumes

Proceedings of The XXV International Symposium on Lattice Field Theory — PoS(LATTICE 2007)

We present recent results on the Landau gauge gluon and ghost propagators in SU(3) pure gauge theory at Wilson β = 5.7 for lattice sizes up to 80 4 corresponding to physical volumes up to (13.2 fm) 4. In particular, we focus on finite-volume and Gribov-copy effects. We employ a gauge-fixing method that combines a simulated annealing algorithm with finalizing overrelaxation. We find the gluon propagator for the largest volumes to become flat at q 2 ∼ 0.01 GeV 2. Although not excluded by our data, there is still no clear indication of a gluon propagator tending towards zero in the zero-momentum limit. New data for the ghost propagator are reported, too.

SU(3) Landau gauge gluon and ghost propagators using the logarithmic lattice gluon field definition

Physical Review D, 2011

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 (NSPT). 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 the 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 NSPT.

Lattice Results on Gluon and Ghost Propagators in Landau Gauge

Particle Physics on the Eve of LHC - Proceedings of the Thirteenth Lomonosov Conference on Elementary Particle Physics, 2009

We present clear evidence of strong effects of Gribov copies in Landau gauge gluon and ghost propagators computed on the lattice at small momenta by employing a new approach to Landau gauge fixing and a more effective numerical algorithm. It is further shown that the new approach substantially decreases notorious finite-volume effects.

Large momentum behavior of the ghost propagator in SU(3) lattice gauge theory

Physical Review D, 2005

We study the asymptotic behavior of the ghost propagator in the quenched SU(3) lattice gauge theory with Wilson action. The study is performed on lattices with a physical volume fixed around 1.6 fm and different lattice spacings: 0.100 fm, 0.070 fm and 0.055 fm. We implement an efficient algorithm for computing the Faddeev-Popov operator on the lattice. We are able to extrapolate the lattice data for the ghost propagator towards the continuum and to show that the extrapolated data on each lattice can be described up to four-loop perturbation theory from 2.0 GeV to 6.0 GeV. The three-loop values are consistent with those extracted from previous perturbative studies of the gluon propagator. However the effective Λ MS scale which reproduces the data does depend strongly upon the order of perturbation theory and on the renormalization scheme used in the parametrization. We show how the truncation of the perturbative series can account for the magnitude of the dependency in this energy range. The contribution of non-perturbative corrections will be discussed elsewhere.

First Lattice Study of Ghost Propagators in SU(2) and SU(3) Gauge Theories

1995

We present a numerical study of the ghost propagators inLandau gauge for SU(2) and SU(3) gauge theories at fi=2.7and fi=6.0, respectively. Analyzing different lattice sizes upto 324, we find small finite size effects. Down to the smallestavailable momenta, we observe no evidence for dipolebehaviour of the ghost propagators.1 IntroductionThe gluon propagator, P , albeit a non-gauge-invariant quantity, is consideredof prime interest in the quest to gain intuitive insight into the...

Landau gauge ghost propagator and running coupling in S U ( 2 ) lattice gauge theory

Physical Review D, 2015

We study finite (physical) volume and scaling violation effects of Landau gauge ghost propagator as well as of the running coupling αs(p) in the SU (2) lattice gauge theory. We consider lattices with physical sizes between 3 and 7 fm and values of spacing a between 0.2 and 0.07 fm. To fix the gauge we apply an efficient gauge fixing method aimed at finding extrema as close as possible to the global maximum of the gauge functional. We show that finite volume effects turn out to be rather small for momenta |p| > ∼ 0.6 GeV. The relative scaling violations for αs(p) do not exceed 10% within the bare coupling range β = 4/g 2 0 ∈ [2.30, 2.55] for the same momentum region and decreases quickly with increasing |p|. Our results testify in favor of the decoupling behavior.

Asymptotic behavior of the ghost propagator in SU3 lattice gauge theory

We study the asymptotic behavior of the ghost propagator in the quenched SU(3) lattice gauge theory with Wilson action. The study is performed on lattices with a physical volume fixed around 1.6 fm and different lattice spacings: 0.100 fm, 0.070 fm and 0.055 fm. We implement an efficient algorithm for computing the Faddeev-Popov operator on the lattice. We are able to extrapolate the lattice data for the ghost propagator towards the continuum and to show that the extrapolated data on each lattice can be described up to four-loop perturbation theory from 2.0 GeV to 6.0 GeV. The three-loop values are consistent with those extracted from previous perturbative studies of the gluon propagator. However the effective Λ MS scale which reproduces the data does depend strongly upon the order of perturbation theory and on the renormalization scheme used in the parametrization. We show how the truncation of the perturbative series can account for the magnitude of the dependency in this energy range. The contribution of non-perturbative corrections will be discussed elsewhere.

Landau gauge gluon and ghost propagators at finite temperature from quenched lattice QCD

2011

The behavior of the Landau gauge gluon and ghost propagators is studied in pure SU(3) gauge theory at non-zero temperature on the lattice. We concentrate on the momentum range [0.6, 2.0] GeV. For the longitudinal as well as for the transverse component of the gluon propagator we extract the continuum limit. We demonstrate the smallness of finite-size and Gribov-copy effects