25 research outputs found
Gluonic Higgs Scalar, Abelianization and Monopoles in QCD -- Similarity and Difference between QCD in the MA Gauge and the NAH Theory
We study the similarity and the difference between QCD in the maximally
abelian (MA) gauge and the nonabelian Higgs (NAH) theory by introducing the
``gluonic Higgs scalar field'' corresponding to the
``color-direction'' of the nonabelian gauge connection. The infrared-relevant
gluonic mode in QCD can be extracted by the projection along the
color-direction like the NAH theory. This projection is
manifestly gauge-invariant, and is mathematically equivalent to the ordinary MA
projection. Since obeys the adjoint gauge transformation and is
diagonalized in the MA gauge, behaves as the Higgs scalar in the
NAH theory, and its hedgehog singularity provides the magnetic monopole in the
MA gauge like the NAH theory. We observe this direct correspondence between the
monopole appearing in the MA gauge and the hedgehog singularity of in lattice QCD, when the gluon field is continuous as in the SU()
Landau gauge. In spite of several similarities, QCD in the MA gauge largely
differs from the NAH theory in the two points: one is infrared monopole
condensation, and the other is infrared enhancement of the abelian correlation
due to monopole condensation.Comment: Talk given at 16th International Conference on Particles and Nuclei
(PANIC 02), Osaka, Japan, 30 Sep - 4 Oct 200
Y-type Flux-Tube Formation and Gluonic Excitations in Baryons: From QCD to Quark Model
Using SU(3) lattice QCD, we perform the first systematic study for the
ground-state three-quark (3Q) potential and the 1st
excited-state 3Q potential , {\it i.e.}, the energies of
the ground state and the 1st excited state of the gluon field in the presence
of the static three quarks. From the accurate and thorough calculation for more
than 300 different patterns of 3Q systems, the static ground-state 3Q potential
is found to be well described by the Coulomb plus
Y-type linear potential, {\it i.e.}, Y-Ansatz, within 1%-level deviation. As a
clear evidence for Y-Ansatz, Y-type flux-tube formation is actually observed on
the lattice in maximally-Abelian projected QCD. For more than 100 patterns of
3Q systems, we calculate the 1st excited-state 3Q potential in quenched lattice QCD, and find the gluonic excitation energy to be about 1
GeV. This large gluonic-excitation energy is conjectured to ensure the success
of the quark model for the low-lying hadrons even without gluonic excitations.Comment: Talk given at International Conference on Color Confinement and
Hadrons in Quantum Chromodynamics - Confinement 2003, RIKEN, Japan, 21-24 Jul
200
Chiral Symmetry Breaking in the Dual Ginzburg-Landau Theory
Confinement and chiral symmetry breaking are the most fundamental phenomena
in Quark Nuclear Physics, where hadrons and nuclei are described in terms of
quarks and gluons. The dual Ginzburg-Landau (DGL) theory, which contains
monopole fields as the most essential degrees of freedom and their condensation
in the vacuum, is modeled to describe quark confinement in strong connection
with QCD. We then demonstrate that the DGL theory is able to describe the
spontaneous break down of the chiral symmetry.Comment: Talk presented by H. Toki at the Joint Japan-Australia Workshop on
``Quarks, Hadrons and Nuclei'', 15 - 24 Nov. 1995, in Adelaide, Australia, 7
pages, Plain Latex, 4 postscript figures (included in a separate .uu file