2,616 research outputs found
Infrared behavior of the Faddeev-Popov operator in Coulomb gauge QCD
We calculate the eigenvalue distribution of the Faddeev-Popov operator in
Coulomb gauge QCD using quenched SU(3) lattice simulation. In the confinement
phase, the density of the low-lying eigenvalues increases with lattice volume,
and the confinement criterion is satisfied. Moreover, even in the deconfinement
phase, the behavior of the FP eigenvalue density is qualitatively the same as
in the confinement phase. This is consistent with the fact that the
color-Coulomb potential is not screened in the deconfined phase.Comment: 10 pages, 10 figure
Scaling study of the gluon propagator in Coulomb gauge QCD on isotropic and anisotropic lattices
We calculate the transverse and time-time components of the instantaneous
gluon propagator in Coulomb gauge QCD by using an SU(3) quenched lattice
simulation on isotropic and anisotropic lattices. We find that the gluon
propagators suffer from strong discretization effects on the isotropic lattice;
on the other hand, those on the anisotropic lattices give a better scaling.
Moreover, on these two type of lattices the transverse parts are significantly
suppressed in the infrared region and have a turnover at about 500 [MeV]. The
high resolution to the temporal direction due to the anisotropy yields small
discretization errors for the time-time gluon propagators, which also show an
infrared enhancement as expected in the Gribov-Zwanziger confinement scenario.Comment: 29 pages, 18 figure
Properties of Color-Coulomb String Tension
We study the properties of the color-Coulomb string tension obtained from the
instantaneous part of gluon propagators in Coulomb gauge using quenched SU(3)
lattice simulation.
In the confinement phase, the dependence of the color-Coulomb string tension
on the QCD coupling constant is smaller than that of the Wilson loop string
tension. On the other hand, in the deconfinement phase, the color-Coulomb
string tension does not vanish even for , the temperature
dependence of which is comparable with the magnetic scaling, dominating the
high temperature QCD. Thus, the color-Coulomb string tension is not an order
parameter of QGP phase transition.Comment: 17 pages, 5 figures; one new figure added, typos corrected, version
to appear in PR
Spectral sum for the color-Coulomb potential in SU(3) Coulomb gauge lattice Yang-Mills theory
We discuss the essential role of the low-lying eigenmodes of the
Faddeev-Popov (FP) ghost operator on the confining color-Coulomb potential
using SU(3) quenched lattice simulations in the Coulomb gauge. The
color-Coulomb potential is expressed as a spectral sum of the FP ghost operator
and has been explored by partially summing the FP eigenmodes. We take into
account the Gribov copy effects that have a great impact on the FP eigenvalues
and the color-Coulomb potential. We observe that the lowest eigenvalue vanishes
in the thermodynamic limit much faster than that in the Landau gauge. The
color-Coulomb potential at large distances is governed by the near-zero FP
eigenmodes; in particular, the lowest one accounts for a substantial portion of
the color-Coulomb string tension comparable to the Wilson string tension.Comment: 14 pages, 14 figure
Roles of the tensor and pairing correlations on the halo formation in 11Li
We study the roles of the tensor and pairing correlations on the halo
formation in 11Li with an extended 9Li+n+n model. We first solve the ground
state of 9Li in the shell model basis by taking 2p-2h states using the Gaussian
functions with variational size parameters to take into account the tensor
correlation fully. In 11Li, the tensor and pairing correlations in 9Li are
Pauli-blocked by additional two neutrons, which work coherently to make the
configurations containing the 0p1/2 state pushed up and close to those
containing the 1s1/2 state. Hence, the pairing interaction works efficiently to
mix the two configurations by equal amount and develop the halo structure in
11Li. For 10Li, the inversion phenomenon of s- and p-states is reproduced in
the same framework. Our model furthermore explains the recently observed
Coulomb breakup strength and charge radius for 11Li.Comment: 8 pages, 5 figure
Study of the effect of the tensor correlation in oxygen isotopes with the charge- and parity-projected Hartree-Fock method
Recently, we developed a mean-field-type framework which treats the
correlation induced by the tensor force. To exploit the tensor correlation we
introduce single-particle states with the parity and charge mixing. To make a
total wave function have a definite charge number and a good parity, the charge
number and parity projections are performed. Taking a variation of the
projected wave function with respect to single-particle states a
Hartree-Fock-like equation, the charge- and parity-projected Hartree-Fock
equation, is obtained. In the charge- and parity-projected Hartree-Fock method,
we solve the equation selfconsistently. In this paper we extend the charge- and
parity-projected Hartree-Fock method to include a three-body force, which is
important to reproduce the saturation property of nuclei in mean-field
frameworks. We apply the charge- and parity-projected Hartree-Fock method to
sub-closed-shell oxygen isotopes (14O, 16O, 22O, 24O, and 28O) to study the
effect of the tenor correlation and its dependence on neutron numbers. We
obtain reasonable binding energies and matter radii for these nuclei. It is
found that relatively large energy gains come from the tensor force in these
isotopes and there is the blocking effect by occupied neutron orbits on the
tensor correlation
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