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Visualizations of Quantum Chromodynamics

Centre for the Subatomic Structure of Matter (CSSM) and Department of Physics, University of Adelaide, 5005 Australia
Copyright © 2003, 2004

  • This page provides a collection of the most recent visualizations of Quantum Chromodynamics (QCD), the underlying theory of the strong interactions. As a key component of the Standard Model of the Universe, QCD describes the interactions between quarks and gluons as they compose particles such as the proton or neutron.

    State of the art order a4-improved lattice operators are used in creating the animations, including the three-loop improved lattice gauge action and the five-loop improved lattice field strength tensor.

    The animaton at right was featured in Prof. Frank Wilczek's 2004 Nobel Prize Lecture.



  • This animation shows the suppression of the QCD vacuum from the region between a quark-antiquark pair illustrated by the coloured spheres. The separation of the quarks varies from 0.125 fm to 2.25 fm, the latter being about 1.3 times the diameter of a proton. The surface plot illustrates the reduction of the vacuum action density in a plane passing through the centers of the quark-antiquark pair. The vector field illustrates the gradient of this reduction. The tube joining the two quarks reveals the positions in space where the vacuum action is maximally expelled and corresponds to the famous "flux tube" of QCD. As the separation between the quarks changes the tube gets longer but the diameter remains approximately constant. As it costs energy to expel the vacuum field fluctuations, a linear confinement potential is felt between quarks.

    A high quality animation is available:

    A high quality image is also available:


  • The manner in which QCD vacuum fluctuations are expelled from the interior region of a baryon like the proton is animated at right. The positions of the three quarks composing the proton are illustrated by the coloured spheres. The surface plot illustrates the reduction of the vacuum action density in a plane passing through the centers of the quarks. The vector field illustrates the gradient of this reduction. The positions in space where the vacuum action is maximally expelled from the interior of the proton are also illustrated by the tube-like structures, exposing the presence of flux tubes. A key point of interest is the distance at which the flux-tube formation occurs. The animation indicates that the transition to flux-tube formation occurs when the distance of the quarks from the centre of the triangle (< r >) is greater than 0.5 fm. Again, the diameter of the flux tubes remains approximately constant as the quarks move to large separations. As it costs energy to expel the vacuum field fluctuations, a linear confinement potential is felt between quarks in baryons as well as mesons.

    A high quality animation is available:

    A high quality picture is also available:

    Further details are available in the publicaton
    ``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 and A. G. Williams
    Phys. Rev. D 76, 114512 (2007) 16 pp.
    [arXiv:hep-lat/0606016]



Contributions from Sundance Bilson-Thompson on improved operator construction and Ben Lasscock and James Zanotti on the vacuum response to static quarks, are gratefully acknowledged.

This research is enabled by the NCI National Facility and eResearch SA through generous grants of supercomputing time. This research is supported by the Australian Research Council.

For further information, try the web adventure The Origin of Mass, download the Virtual Reality Up Close Presentation or visit the Archives.

For copyright information, please contact Derek Leinweber.