390 research outputs found
Polyakov Loops and Magnetic Screening from Monopoles in SU(2) Lattice Gauge Theory
We present results from magnetic monopoles in lattice gauge theory at
finite temperature. The lattices are , for
, at . Quantities discussed are: the spacial
string tension, Polyakov loops, and the screening of timelike and spacelike
magnetic currents.Comment: 5 pages, four Postscript figures, Late
Monopoles at Finite Volume and Temperature in SU(2) Lattice Gauge Theory
We resolve a discrepancy between the SU(2) spacial string tension at finite
temperature, and the value obtained by monopoles in the maximum Abelian gauge.
Previous work had incorrectly omitted a term due to Dirac sheets. When this
term is included, the monopole and full SU(2) determinations of the spacial
string tension agree to within the statistical errors of the monopole
calculation.Comment: 8 pages, Latex files: msum.tex,msum.aux packaged with uufile
Confinement by Monopoles in the Positive Plaquette Model of SU(2) Lattice Gauge Theory
Confinement via 't Hooft-Mandelstam monopoles is studied for the positive
plaquette model in SU(2) lattice gauge theory. Positive plaquette model
configurations are projected into the maximum abelian gauge and the magnetic
current extracted. The resulting magnetic current is used to compute monopole
contributions to Wilson loops and extract a monopole contribution to the string
tension. As was previously found for the Wilson action, the monopole
contribution to the string tension agrees with the string tension calculated
directly from the SU(2) links. The fact that the positive plaquette model
suppresses Z2 monopoles and vortices is discussed.Comment: 8 pages, one Postscript figure, Latex, uses psfig files:
posplaq.tex,posplaq.aux,pp_1_3.ps packaged with uufile
Magnetic Monopoles as Agents of Chiral Symmetry Breaking in U(1) Lattice Gauge Theory
We present results suggesting that magnetic monopoles can account for chiral
symmetry breaking in abelian gauge theory. Full U(1) configurations from a
lattice simulation are factorized into magnetic monopole and photon
contributions. The expectation is computed using the monopole
configurations and compared to results for the full U(1) configurations. It is
shown that excellent agreement between the two values of is
obtained if the effect of photons, which "dress" the composite operator
psibarpsi, is included. This can be estimated independently by measurements of
the physical fermion mass in the photon background.Comment: 14 pages REVTeX, including 5 figure
The Gribov Ambiguity for Maximal Abelian and Center Gauges in SU(2) Lattice Gauge Theory
We present results for the fundamental string tension in SU(2) lattice gauge
theory after projection to maximal abelian and direct maximal center gauges. We
generate 20 Gribov copies/configuration. Abelian and center projected string
tensions slowly decrease as higher values of the gauge functionals are reached.Comment: 3 pages, latex, 1 postscript figure, presented at Lattice
2000(Topology and Vacuum
The Maximal Abelian Gauge, Monopoles, and Vortices in SU(3) Lattice Gauge Theory
We report on calculations of the heavy quark potential in SU(3) lattice gauge
theory. Full SU(3) results are compared to three cases which involve
gauge-fixing and projection. All of these start from the maximal abelian gauge
(MAG), in its simplest form. The first case is abelian projection to U(1)xU(1).
The second keeps only the abelian fields of monopoles in the MAG. The third
involves an additional gauge-fixing to the indirect maximal center gauge
(IMCG), followed by center projection to Z(3). At one gauge
fixing/configuration, the string tensions calculated from MAG U(1)xU(1), MAG
monopoles, and IMCG Z(3) are all less than the full SU(3) string tension. The
projected string tensions further decrease, by approximately 10%, when account
is taken of gauge ambiguities. Comparison is made with corresponding results
for SU(2). It is emphasized that the formulation of the MAG is more subtle for
SU(3) than for SU(2), and that the low string tensions may be caused by the
simple MAG form used. A generalized MAG for SU(3) is formulated.Comment: 22 pages, latex, 2 postscript figures. Replaced version has added
data at beta=6.0, analysis of Gribov ambiguities, extended tables of results,
discussion of scalin
The NASA Langley laminar-flow-control experiment on a swept, supercritical airfoil: Evaluation of initial perforated configuration
The initial evaluation of a large-chord, swept, supercritical airfoil incorporating an active laminar-flow-control (LFC) suction system with a perforated upper surface is documented in a chronological manner, and the deficiencies in the suction capability of the perforated panels as designed are described. The experiment was conducted in the Langley 8-Foot Transonic Pressure Tunnel. Also included is an evaluation of the influence of the proximity of the tunnel liner to the upper surface of the airfoil pressure distribution
Abelian Links, Monopoles and Glueballs in SU(2) Lattice Gauge Theory
We investigate the masses of 0+ and 2+ glueballs in SU(2) lattice gauge
theory using abelian projection to the maximum abelian gauge. We calculate
glueball masses using both abelian links and monopole operators. Both methods
reproduce the known full SU(2) results quantitatively. Positivity problems
present in the abelian projection are discussed. We study the dependence of the
glueball masses on magnetic current loop size, and find that the 0+ state
requires a much greater range of sizes than does the 2+ state.Comment: 18 pages, latex, 4 postscript figure
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