21,099 research outputs found
Center vortex model for the infrared sector of Yang-Mills theory
A model for the infrared sector of SU(2) Yang-Mills theory, based on magnetic
vortices represented by (closed) random surfaces, is presented. The model
quantitatively describes both confinement (including the finite-temperature
transition to a deconfined phase) and the topological susceptibility of the
Yang-Mills ensemble. A first (quenched) study of the spectrum of the Dirac
operator furthermore yields a behavior for the chiral condensate which is
compatible with results obtained in lattice gauge theory.Comment: Lattice2001(confinement) proceedings, 3 pages, 3 ps figure
Center vortex model for the infrared sector of SU(3) Yang-Mills theory: Topological susceptibility
The topological susceptibility of the SU(3) random vortex world-surface
ensemble, an effective model of infrared Yang-Mills dynamics, is investigated.
The model is implemented by composing vortex world-surfaces of elementary
squares on a hypercubic lattice, supplemented by an appropriate specification
of vortex color structure on the world-surfaces. Topological charge is
generated in this picture by writhe and self-intersection of the vortex
world-surfaces. Systematic uncertainties in the evaluation of the topological
charge, engendered by the hypercubic construction, are discussed. Results for
the topological susceptibility are reported as a function of temperature and
compared to corresponding measurements in SU(3) lattice Yang-Mills theory. In
the confined phase, the topological susceptibility of the random vortex
world-surface ensemble appears quantitatively consistent with Yang-Mills
theory. As the temperature is raised into the deconfined regime, the
topological susceptibility falls off rapidly, but significantly less so than in
SU(3) lattice Yang-Mills theory. Possible causes of this deviation, ranging
from artefacts of the hypercubic description to more physical sources, such as
the adopted vortex dynamics, are discussed.Comment: 30 pages, 6 figure
Susceptibility of Monte-Carlo Generated Projected Vortices
We determine the topological susceptibility from center projected vortices
and demonstrate that the topological properties of the SU(2) Yang-Mills vacuum
can be extracted from the vortex content. We eliminate spurious ultraviolet
fluctuations by two different smoothing procedures. The extracted
susceptibility is comparable to that obtained from full field configurations.Comment: 3 pages, 4 figures; Lattice2001(confinement
Center vortex model for the infrared sector of SU(4) Yang-Mills theory: String tensions and deconfinement transition
A random vortex world-surface model for the infrared sector of SU(4)
Yang-Mills theory is constructed, focusing on the confinement properties and
the behavior at the deconfinement phase transition. Although the corresponding
data from lattice Yang-Mills theory can be reproduced, the model requires a
more complex action and considerably more tuning than the SU(2) and SU(3) cases
studied previously. Its predictive capabilities are accordingly reduced. This
behavior has a definite physical origin, which is elucidated in detail in the
present work. As the number of colors is raised in Yang-Mills theory, the
corresponding infrared effective vortex description cannot indefinitely
continue to rely on dynamics determined purely by vortex world-surface
characteristics; additional color structures present on the vortices begin to
play a role. As evidenced by the modeling effort reported here, definite
signatures of this behavior appear in the case of four colors.Comment: 24 pages, 7 figures containing 8 ps file
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