466 research outputs found
Construction of staples in lattice gauge theory on a parallel computer
We propose a simple method to construct staples in lattice gauge theory with
Wilson action on a parallel computer. This method can be applicable to any
dimensional system and to any dimensional division without difficulty.
Furthermore this requires rather small working area to realize gauge simulation
on a parallel computer.Comment: 4 pages of A4 forma
Measurement of the Kerr Spin Parameter by Observation of a Compact Object's Shadow
A black hole casts a shadow as an optical appearance because of its strong
gravitational field. We study how to determine the spin parameter and the
inclination angle by observing the apparent shape of the shadow, which is
distorted mainly by those two parameters. Defining some observables
characterizing the apparent shape (its radius and distortion parameter), we
find that the spin parameter and inclination angle of a Kerr black hole can be
determined by the observation. This technique is also extended to the case of a
Kerr naked singularity.Comment: 9 pages, 11 figures; v2: references added, typos corrected; v3:
accepted for publication in Physical Review
Dual Superconductor Mechanism of Confinement on the Lattice
We investigate the dual superconductor mechanism of confinement for pure
SU(2) lattice gauge theory in the maximally abelian gauge. We focus on the the
dual Meissner effect. We find that the transverse distribution of the
longitudinal chromoelectric field due to a static quark-antiquark pair
satisfies the dual London equation. Moreover we show that the size of the flux
tube scales according to asymptotic freedom.Comment: LaTeX, 9 pages, 6 figures available as a PostScript file from L.
Cosmai, BARI - TH 110/9
Creutz Ratios From Color-Truncated Lattice Configurations
We investigate whether information about Creutz ratios is encoded,
separately, in each gluon color component of numerically generated lattice
configurations. Working in SU(2) lattice gauge theory in Landau gauge, we set
two of the three gluon color components to zero, and compensate for the loss of
two-thirds of the fluctuation by simply rescaling the remaining component by a
factor of . Creutz ratios are then computed with this "abelianized"
configuration. We find that the Creutz ratios of loops constructed from
abelianized links converge to the usual Creutz ratios in the scaling regime.Comment: 5 pages, plain LaTeX, one figur
On the perfect lattice actions of abelian-projected SU(2) QCD
We study the perfect lattice actions of abelian-projected SU(2) gluodynamics.
Using the BKT and duality transformations on the lattice, an effective string
model is derived from the direction-dependent quadratic monopole action,
obtained numerically from SU(2) gluodynamics in maximally abelian gauge. The
string tension and the restoration of continuum rotational invariance are
investigated using strong coupling expansion of lattice string model
analytically. We also found that the block spin transformation can be performed
analytically for the quadratic monopole action.Comment: 3 pages, Latex, 1 figures; talk presented at LATTICE9
Various representations of infrared effective lattice QCD
We study various representations of the infrared effective theory of SU(2)
gluodynamics starting from the monopole action derived recently.
We determine the coupling constants in the abelian-Higgs model directly from
lattice QCD and evaluate the type of the QCD vacuum. The string action is
derived using the BKT transformation on the lattice. At the classical level
this action reproduces the physical string tension with a good accuracy.Comment: 3 pages, LaTeX, 2 figures; talk presented at LATTICE9
Large Dual Transformations and the Petrov-Diakonov Representation of the Wilson Loop
In this work, based on the Petrov-Diakonov representation of the Wilson loop
average W in the SU(2) Yang-Mills theory, together with the Cho-Fadeev-Niemi
decomposition, we present a natural framework to discuss possible ideas
underlying confinement and ensembles of defects in the continuum. In this
language we show how for different ensembles the surface appearing in the
Wess-Zumino term in W can be either decoupled or turned into a variable, to be
summed together with gauge fields, defects and dual fields. This is discussed
in terms of the regularity properties imposed by the ensembles on the dual
fields, thus precluding or enabling the possibility of performing the large
dual transformations that would be necessary to decouple the initial surface.Comment: 35 pages, LaTeX, corrected version, accepted for publication in Phys.
Rev.
Lepton distribution as a probe of new physics in production and decay of the t quark and its polarization
We investigate the possibilities of studying new physics in various processes
of t-quark production using kinematical distributions of the secondary lepton
coming from decay of t quarks. We show that the angular distributions of the
secondary lepton are insensitive to the anomalous tbW vertex and hence are pure
probes of new physics in a generic process of t-quark production. The energy
distribution of the lepton is distinctly affected by anomalous tbW couplings
and can be used to analyze them independent of the production process of t
quarks. The effects of t polarization on the distributions of the decay lepton
are demonstrated for top-pair production process at a gamma-gamma collider
mediated by a heavy Higgs boson.Comment: 15 pages, 7 figures, uses axodraw.sty (included), references added.
v3 to appear in Journal of High Energy Physics. Incorporates minor changes in
the discussion on radiative corrections which do not affect the results. Typo
in reference correcte
Evidence of Strong Correlation between Instanton and QCD-monopole on SU(2) Lattice
The correlation between instantons and QCD-monopoles is studied both in the
lattice gauge theory and in the continuum theory. An analytical study in the
Polyakov-like gauge, where is diagonalized, shows that the
QCD-monopole trajectory penetrates the center of each instanton, and becomes
complicated in the multi-instanton system. Using the SU(2) lattice with ,
the instanton number is measured in the singular (monopole-dominating) and
regular (photon-dominating) parts, respectively. The monopole dominance for the
topological charge is found both in the maximally abelian gauge and in the
Polyakov gauge.Comment: 4 pages, Latex, 3 figures. Talk presented by H. Suganuma at
International Symposium on 'Lattice Field Theory', July 11 - 15, 1995,
Melbourne, Australi
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