1,256 research outputs found
Confinement and Topological Charge in the Abelian Gauge of QCD
We study the relation between instantons and monopoles in the abelian gauge.
First, we investigate the monopole in the multi-instanton solution in the
continuum Yang-Mills theory using the Polyakov gauge. At a large instanton
density, the monopole trajectory becomes highly complicated, which can be
regarded as a signal of monopole condensation. Second, we study instantons and
monopoles in the SU(2) lattice gauge theory both in the maximally abelian (MA)
gauge and in the Polyakov gauge. Using the lattice, we find
monopole dominance for instantons in the confinement phase even at finite
temperatures. A linear-type correlation is found between the total
monopole-loop length and the integral of the absolute value of the topological
density (the total number of instantons and anti-instantons) in the MA gauge.
We conjecture that instantons enhance the monopole-loop length and promote
monopole condensation.Comment: 3 pages, LaTeX, Talk presented at LATTICE96(topology
Confinement Properties in the Multi-Instanton System
We investigate the confinement properties in the multi-instanton system,
where the size distribution is assumed to be for the large
instanton size . We find that the instanton vacuum gives the area law
behavior of the Wilson loop, which indicates existence of the linear confining
potential. In the multi-instanton system, the string tension increases
monotonously with the instanton density, and takes the standard value for the density . Thus, instantons
directly relate to color confinement properties.Comment: Talk presented by M. Fukushima at ``Lattice '97'', the International
Symposium on Lattice Field Theory, 22 - 26 July 1997, in Edinburgh, Scotland,
3 pages, Plain Late
Instanton and Monopole in External Chromomagnetic Fields
We study properties of instanton and monopole in an external chromomagnetic
field. Generally, the 't Hooft ansatz is no longer a solution of the Yang-Mills
field equation in the presence of external fields. Therefore, we investigate a
stabilized instanton solution with minimal total Yang-Mills action in a
nontrivial topological sector. With this aim, we consider numerical
minimization of the action with respect to the global color orientation, the
anisotropic scale transformation and the local gauge-like transformation
starting from a simple superposed gauge field of the 't Hooft ansatz and the
external color field. Here, the external color field is, for simplicity, chosen
to be a constant Abelian magnetic field along a certain direction. Then, the
4-dimensional rotational symmetry O(4) of the instanton solution is reduced to
two 2-dimensional rotational symmetries due to the effect of
a homogeneous external field. In the space \mib{R}^{3} at fixed , we find
a quadrupole deformation of this instanton solution. In the presence of a
magnetic field , a prolate deformation occurs along the direction of
. Contrastingly, in the presence of an electric field an
oblate deformation occurs along the direction of . We further discuss
the local correlation between the instanton and the monopole in the external
field in the maximally Abelian gauge. The external field affects the appearance
of the monopole trajectory around the instanton. In fact, a monopole and
anti-monopole pair appears around the instanton center, and this monopole loop
seems to partially screen the external field.Comment: 15 pages,8 figure
Dirac-mode expansion for confinement and chiral symmetry breaking
We develop a manifestly gauge-covariant expansion and projection using the
eigen-mode of the QCD Dirac operator. Applying this method to the Wilson loop
and the Polyakov loop, we perform a direct analysis of the correlation between
confinement and chiral symmetry breaking in SU(3) lattice QCD calculation on
6^4 at beta=5.6 at the quenched level. Notably, the Wilson loop is found to
obey the area law, and the slope parameter corresponding to the string tension
or the confinement force is almost unchanged, even after removing the low-lying
Dirac modes, which are responsible to chiral symmetry breaking. We find also
that the Polyakov loop remains to be almost zero even without the low-lying
Dirac modes, which indicates the Z_3-unbroken confinement phase. These results
indicate that one-to-one correspondence does not hold between confinement and
chiral symmetry breaking in QCD.Comment: 7 pages, 6 figures, Talk given at Conference: Lattice 201
The System of Multi Color-flux-tubes in the Dual Ginzburg-Landau Theory
We study the system of multi color-flux-tubes in terms of the dual Ginzburg
-Landau theory. We consider two ideal cases, where the directions of all the
color-flux-tubes are the same in one case and alternative in the other case for
neighboring flux-tubes. We formulate the system of multi color-flux -tubes by
regarding it as the system of two color-flux-tubes penetrating through a two
dimensional sphere surface. We find the multi flux-tube configuration becomes
uniform above some critical flux-tube number density . On the other hand, the inhomogeneity on the color electric
distribution appears when the flux-tube density is smaller than . We
discuss the relation between the inhomogeneity in the color-electric
distribution and the flux-tube number density in the multi-flux-tube system
created during the QGP formation process in the ultra-relativistic heavy-ion
collision.Comment: 17 pages, Revtex, ( 7 figures - available on request from
[email protected]
Clustering of Monopoles in the Instanton Vacuum
We generate a random instanton vacuum with various densities and size
distributions. We perform numerically the maximally abelian gauge fixing of
these configurations in order to find monopole trajectories induced by
instantons. We find that instanton-induced monopole loops form enormous
clusters occupying the whole physical volume, provided instantons are
sufficiently dense. It indicates that confinement might be caused by
instantons.Comment: 7 pages, Plain Latex, (3 figures - available on request from
[email protected]
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
- âŠ