Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · hep-lat/0606016

Gluon flux-tube distribution and linear confinement in baryons

F. Bissey·F-G. Cao·A. R. Kitson·A. I. Signal·D. B. Leinweber·B. G. Lasscock·A. G. Williams
View original source ↗Read source document ↗Export metadata ↓

Abstract

We have observed the formation of gluon flux-tubes within baryons using lattice QCD techniques. A high-statistics approach, based on translational and rotational symmetries of the four-dimensional lattice, enables us to observe correlations between vacuum action density and quark positions in a completely gauge independent manner. This contrasts with earlier studies which used gauge-dependent smoothing techniques. We used 200 O(a^2) improved quenched QCD gauge-field configurations on a 16^3x32 lattice with a lattice spacing of 0.123 fm. In the presence of static quarks flux tubes representing the suppression of gluon-field fluctuations are observed. We have analyzed 11 L-shapes and 8 T and Y shapes of varying sizes in order to explore a variety of flux-tube topologies, including the ground state. At large separations, Y-shape flux-tube formation is observed. T-shaped paths are observed to relax towards a Y-shaped topology, whereas L-shaped paths give rise to a large potential energy. We do not find any evidence for the formation of a Delta-shaped flux-tube (empty triangle) distribution. However, at small quark separations, we observe an expulsion of gluon-field fluctuations in the shape of a filled triangle with maximal expulsion at the centre of the triangle. Having identified the precise geometry of the flux distribution, we are able to perform quantitative comparison between the length of the flux-tube and the associated static quark potential. For every source configuration considered we find a universal string tension, and conclude that, for large quark separations, the ground state potential is that which minimizes the length of the flux-tube. The flux tube radius of the baryonic ground state potential is found to be 0.38 \pm 0.03 fm, with vacuum fluctuations suppressed by 7.2 \pm 0.6 %.

Explore related subjects

hep-lat

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

F. Bissey, F-G. Cao, A. R. Kitson, A. I. Signal, D. B. Leinweber, B. G. Lasscock, A. G. Williams. 2007-11-02. Gluon flux-tube distribution and linear confinement in baryons. https://doi.org/10.1103/physrevd.76.114512

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Can multi-level Monte-Carlo address the sign problem in a finite-density Bose gas?

Numerical simulation of field theories with complex actions is frustrated by the sign problem, which causes an exponential growth in statistical sampling noise. A key example of such a theory is QCD at finite baryon chemical potential, which has important applications to the structure of atomic nuclei and neutron stars. Until now, the sign problem has precluded the possibility of first-principles numerical calculations that could provide key insight into these important physical systems. In this work, we propose an approach to avoiding this limitation by applying a reweighting procedure coupled with a multi-level Monte-Carlo sampling algorithm that offers an exponential enhancement of statistics to counteract the sign problem. We test the approach on a simpler model that displays the same sign problem at finite chemical potential. Our results demonstrate the promise of the proposed approach, significantly increasing the range over which precise calculations are possible, and providing improvements all the way up to the phase transition.

hep-lat↗
arXiv2026

A Note On Lattice Definition of Gauge Theories With Chiral Fermions

Because of the fermion doubling problem, it has been a longstanding challenge to describe a lattice algorithm for studying four-dimensional gauge theories coupled to chiral fermions. Recently, an algorithm to do so has been described by Craig, extending partial results in the previous literature. Here we describe a variant of this algorithm, based on interpolating a lattice gauge field over the continuum (as in Craig's work) and coupling the interpolated gauge field to continuum chiral fermions. The same variant was also proposed recently by Hsu. In any dimension and for any anomaly-free representation, this approach can be implemented on a computer in principle, but not in practice by Monte Carlo methods because the chiral fermion path integral is not positive.

hep-lat↗
arXiv2026

2+1 flavor light hadron spectrum with PACS10 configurations

We present the results for the hadron spectrum, the pseudoscalar meson decay constants, and the quark mass ratio in the continuum limit using the ``PACS10'' gauge configurations generated with the $O(a)$-improved Wilson quark action and the Iwasaki gauge action. Numerical simulations are carried out at three lattice spacings keeping the space-time volumes over (10 fm$)^4$ in 2+1 flavor QCD at the physical point. We calculate physical quantities with two choices of conventions to define pseudoexperimental values expected in the isosymmetric QCD. In order to investigate the finite size effects on the physical quantities we have additionally generated the (5.4 fm$)^4$ lattice at the coarsest lattice spacing of $a=0.08487(14)$~fm, which is a hypercube with half the length in each direction compared to the PACS10 configurations. While the finite size effect is hardly observed in comparison of the hadron effective masses on the (10.9 fm$)^4$ and (5.4 fm$)^4$ lattices, the results for the pseudoscalar meson decay constants show discrepancies beyond the error bars. The (5.4 fm$)^4$ lattice also serves for determining the expansion parameters of the pseudoscalar meson masses and decay constants, and the octet baryon masses in terms of the quark masses around the physical point with the aid of the mass reweighting technique. The expansion parameters are used for the fine-tuning of the physical point employing the pseudoexperimental masses of the $π$ meson, $K$ meson, and the $Ξ$ baryon as physical inputs in each convention. We compare the results for the octet baryon masses and the pseudoscalar decay constants in the continuum limit with the corresponding pseudoexperimental values in both conventions. We also discuss the deviation between two results with different conventions. As for the quark mass ratio the result is compared with the recent FLAG summary.

hep-lat↗