1,278 research outputs found
Quark Confinement Physics in Quantum Chromodynamics
We study abelian dominance and monopole condensation for the quark
confinement physics using the lattice QCD simulations in the MA gauge. These
phenomena are closely related to the dual superconductor picture of the QCD
vacuum, and enable us to construct the dual Ginzburg-Landau (DGL) theory as an
useful effective theory of nonperturbative QCD. We then apply the DGL theory to
the studies of the low-lying hadron structure and the scalar glueball
properties.Comment: Talk given at 15th International Conference on Particle and Nuclei
(PANIC 99), Uppsala, Sweden, 10-16 Jun 1999, 4 page
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]
Proposal for exotic-hadron search by fragmentation functions
It is proposed that fragmentation functions should be used to identify exotic
hadrons. As an example, fragmentation functions of the scalar meson f_0(980)
are investigated. It is pointed out that the second moments and functional
forms of the u- and s-quark fragmentation functions can distinguish the
tetraquark structure from . By the global analysis of f_0 (980)
production data in electron-positron annihilation, its fragmentation functions
and their uncertainties are determined. It is found that the current available
data are not sufficient to determine its internal structure, while precise data
in future should be able to identify exotic quark configurations.Comment: 4 pages, 4 figures, revtex, To be published in PR
Survival of charmonia above Tc in anisotropic lattice QCD
We find a strong evidence for the survival of and as
spatially-localized (quasi-)bound states above the QCD critical
temperature , by investigating the boundary-condition dependence of their
energies and spectral functions. In a finite-volume box, there arises a
boundary-condition dependence for spatially spread states, while no such
dependence appears for spatially compact states. In lattice QCD, we find almost
{\it no} spatial boundary-condition dependence for the energy of the
system in and channels for . We also
investigate the spectral function of charmonia above in lattice QCD using
the maximum entropy method (MEM) in terms of the boundary-condition dependence.
There is {\it no} spatial boundary-condition dependence for the low-lying peaks
corresponding to and around 3GeV at . These facts
indicate the survival of and as compact
(quasi-)bound states for .Comment: 4 pages, 1 figur
Infrared Abelian Dominance and Dual Higgs Mechanism in Maximally Abelian Gauge
We study infrared abelian dominance and the dual Higgs mechanism in the
maximally abelian (MA) gauge using the lattice QCD Monte Carlo simulation. In
the MA gauge, the off-diagonal gluon phase tends to be random, and the
off-diagonal gluon acquires the effective mass as 1.2 GeV. From the monopole current in the MA gauge, we extract the dual
gluon field and estimate the dual gluon mass as 0.5 GeV.
The QCD-monopole structure is also investigated in terms of off-diagonal
gluons. From the lattice QCD in the MA gauge, the dual Ginzburg-Landau (DGL)
theory can be constructed as a realistic infrared effective theory based on
QCD.Comment: Talk given at 17th International Symposium on Lattice Field Theory
(LATTICE 99), Pisa, Italy, 29 Jun - 3 Jul 199
Quark Confinement Physics from Quantum Chromodynamics
We show the construction of the dual superconducting theory for the
confinement mechanism from QCD in the maximally abelian (MA) gauge using the
lattice QCD Monte Carlo simulation. We find that essence of infrared abelian
dominance is naturally understood with the off-diagonal gluon mass induced by the MA gauge fixing. In the MA gauge, the
off-diagonal gluon amplitude is forced to be small, and the off-diagonal gluon
phase tends to be random. As the mathematical origin of abelian dominance for
confinement, we demonstrate that the strong randomness of the off-diagonal
gluon phase leads to abelian dominance for the string tension. In the MA gauge,
there appears the macroscopic network of the monopole world-line covering the
whole system. We investigate the monopole-current system in the MA gauge by
analyzing the dual gluon field . We evaluate the dual gluon mass as 0.5GeV in the infrared region, which is the lattice-QCD evidence of
the dual Higgs mechanism by monopole condensation. Owing to infrared abelian
dominance and infrared monopole condensation, QCD in the MA gauge is
describable with the dual Ginzburg-Landau theory.Comment: Invited talk given at KEK-Tanashi International Symposium on Physics
of Hadrons and Nuclei, Tokyo, Japan, 14-17 Dec 199
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