54 research outputs found
Confining string and P-vortices in the indirect Z(2) projection of SU(2) lattice gauge theory
We study the distribution of P-vortices near the confining string in the
indirect Z(2) projection of SU(2) lattice gauge theory. It occurs that the
density of vortices is constant at large distances and strongly suppressed near
the line connecting the test quark-antiquark pair. This means that the
condensate of P-vortices is broken inside the confining string. We also find
that the width of the P-vortex density distribution is proportional to the
logarithm of the distance between the quark and antiquark.Comment: 3 pages, 4 figures, Lattice2002(topology), 2 references added, minor
change
Numerical study of gluon propagators in Maximally Abelian gauge
Propagators of diagonal and off-diagonal gluons are studied numerically in
the Maximally Abelian gauge of the SU(2) lattice gauge theory. We have found
the strong enhancement of the diagonal gluon in the infrared region. The
enhancement factor is about 50 at the smallest available momentum, 325 MeV. We
discuss also various analytical fits to the propagators.Comment: 3 pages, 3 figures, uses espcrc2.sty; Lattice2003(topology
Dirac sheets and gauge fixing in lattice gauge theory
Photon correlators in pure gauge theory for different lattice
actions are considered under the Lorentz gauge condition. They are shown to
depend strongly on the gauge fixing ambiguity and on the corresponding
existence of Dirac sheets. For the Coulomb phase a gauge fixing algorithm is
proposed which avoids Dirac sheets and allows to find the global extremum of
the non-local gauge condition. Sorry, figures are not included and can be sent
by ordinary mail.Comment: 11 pages preprint HU Berlin--IEP--93/2, June 199
Monopole clusters at short and large distances
We present measurements of various geometrical characteristics of monopole
clusters in SU(2) lattice gauge theory. The maximal Abelian projection is
employed and both infinite, or percolating cluster and finite clusters are
considered. In particular, we observe scaling for average length of segments of
the percolating cluster between self-crossings, correlators of vacuum monopole
currents, angular correlation between links along trajectories. Short clusters
are random walks and their spectrum in length corresponds to free particles. At
the hadronic scale, on the other hand, the monopole trajectories are no longer
random walks. Moreover, we argue that the data on the density of finite
clusters suggest that there are long-range correlations between finite clusters
which can be understood as association of the clusters with two-dimensional
surfaces, whose area scales.Comment: 9 pages, 11 figure
New features of the maximal abelian projection
After fixing the Maximal Abelian gauge in SU(2) lattice gauge theory we
decompose the nonabelian gauge field into the so called monopole field and the
modified nonabelian field with monopoles removed. We then calculate respective
static potentials and find that the potential due to the modified nonabelian
field is nonconfining while, as is well known, the monopole field potential is
linear. Furthermore, we show that the sum of these potentials approximates the
nonabelian static potential with 5% or higher precision at all distances
considered. We conclude that at large distances the monopole field potential
describes the classical energy of the hadronic string while the modified
nonabelian field potential describes the string fluctuations. Similar
decomposition was observed to work for the adjoint static potential. A check
was also made of the center projection in the direct center gauge. Two static
potentials, determined by projected and by modified nonabelian field
without component were calculated. It was found that their sum is a
substantially worse approximation of the SU(2) static potential than that found
in the monopole case. It is further demonstrated that similar decomposition can
be made for the flux tube action/energy density.Comment: 8 pages, to appear in the proceedings of the Workshop on
Computational Hadron Physics, Nicosia, September 200
P-vortices and Drama of Gribov Copies
We present results of the careful study of the Gribov copies problem in SU(2)
lattice gauge theory for the direct maximal center projection widely used in
confinement studies. Applying simulated annealing algorithm we demonstrate that
this problem is more severe than it was thought before. The projected (gauge
noninvariant) string tension is not in the agreement with the physical string
tension. We do not find any indications that P-vortices reproduce the full
SU(2) string tension neither in the infinite volume limit nor in the continuum
limit.Comment: 16 pages, 7 figures, Latex2e, typos correcte
Anatomy of the lattice magnetic monopoles
We study the Abelian and non-Abelian action densitynear the monopole in the
maximal Abelian gauge of SU(2) lattice gauge theory. We find that the
non-Abelian action density near the monopoles belonging to the percolating
cluster decreases when we approach the monopole center. Our estimate of the
monopole radius is R_mon ~ 0.04 fm.Comment: 9 pp., Latex2e, 2 figure (epsfig), published versio
A renormalization group invariant scalar glueball operator in the (Refined) Gribov-Zwanziger framework
This paper presents a complete algebraic analysis of the renormalizability of
the operator in the Gribov-Zwanziger (GZ) formalism as
well as in the Refined Gribov-Zwanziger (RGZ) version. The GZ formalism offers
a way to deal with gauge copies in the Landau gauge. We explicitly show that
mixes with other gauge variant operators, and we determine
the mixing matrix to all orders, thereby only using algebraic arguments.
The mixing matrix allows us to uncover a renormalization group invariant
including the operator . With this renormalization group
invariant, we have paved the way for the study of the lightest scalar glueball
in the GZ formalism. We discuss how the soft breaking of the BRST symmetry of
the GZ action can influence the glueball correlation function. We expect
non-trivial mass scales, inherent to the GZ approach, to enter the pole
structure of this correlation function.Comment: 27 page
Vortex critical behavior at the de-confinement phase transition
The de-confinement phase transition in SU(2) Yang-Mills theory is revisited
in the vortex picture. Defining the world sheets of the confining vortices by
maximal center projection, the percolation properties of the vortex lines in
the hypercube consisting of the time axis and two spatial axis are studied.
Using the percolation cumulant, the temperature for the percolation transition
is seen to be in good agreement with the critical temperature of the thermal
transition. The finite size scaling function for the cumulant is obtained. The
critical index of the finite size scaling function is consistent with the index
of the 3D Ising model.Comment: 4 pages, 4 PS figures, using revtex4, paragraph and refs added, typo
correcte
Disappearance of the Abrikosov vortex above the deconfining phase transition in SU(2) lattice gauge theory
We calculate the solenoidal magnetic monopole current and electric flux
distributions at finite temperature in the presence of a static quark antiquark
pair. The simulation was performed using SU(2) lattice gauge theory in the
maximal Abelian gauge. We find that the monopole current and electric flux
distributions are quite different below and above the finite temperature
deconfining phase transition point and agree with predictions of the
Ginzburg-Landau effective theory.Comment: 12 pages, Revtex Latex, 6 figures - ps files will be sent upon
reques
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