26,136 research outputs found
Recent results using all-point quark propagators
Pseudofermion methods for extracting all-point quark propagators are
reviewed, with special emphasis on techniques for reducing or eliminating
autocorrelations induced by low eigenmodes of the quark Dirac operator. Recent
applications, including high statistics evaluations of hadronic current
correlators and the pion form factor, are also described.Comment: LateX, 3 pages, 6 eps figures, Lattice2002(algor), corrected some
typo
Unquenched Studies Using the Truncated Determinant Algorithm
A truncated determinant algorithm is used to study the physical effects of
the quark eigenmodes associated with eigenvalues below 420 MeV. This initial
high statistics study focuses on coarse () lattices (with O()
improved gauge action), light internal quark masses and large physical volumes.
Three features of full QCD are examined: topological charge distributions,
string breaking as observed in the static energy and the eta prime mass.Comment: Lattice2001(confinement); 3pgs(Latex), 4figs.(ps
Hadronic Correlators from All-point Quark Propagators
A method for computing all-point quark propagators is applied to a variety of
processes of physical interest in lattice QCD. The method allows, for example,
efficient calculation of disconnected parts and full momentum-space 2 and 3
point functions. Examples discussed include: extraction of chiral Lagrangian
parameters from current correlators, the pion form factor, and the unquenched
eta-prime.Comment: LATTICE01(Algorithms and Machines
Physical Effects of Infrared Quark Eigenmodes in LQCD
A truncated determinant algorithm is used to study the physical effects of
the quark eigenmodes associated with eigenvalues below 400 MeV. This initial
study focuses on coarse lattices (with O(a^2) improved gauge action), light
internal quark masses and large physical volumes. Four bellwether full QCD
processes are discussed: topological charge distributions, the eta prime
propagator, string breaking as observed in the static energy and the rho decay
into two pions.Comment: LATTICE99(Confinement); 3pgs(Latex), 4figs.(eps
String Breaking in Four Dimensional Lattice QCD
Virtual quark pair screening leads to breaking of the string between
fundamental representation quarks in QCD. For unquenched four dimensional
lattice QCD, this (so far elusive) phenomenon is studied using the recently
developed truncated determinant algorithm (TDA). The dynamical configurations
were generated on an Athlon 650 MHz PC. Quark eigenmodes up to 420 MeV are
included exactly in these TDA studies performed at low quark mass on large
coarse (but O() improved) lattices. A study of Wilson line correlators in
Coulomb gauge extracted from an ensemble of 1000 two-flavor dynamical
configurations reveals evidence for flattening of the string tension at
distances R approximately 1 fm.Comment: 16 pages, 5 figures, Latex (deleted extraneous eps figure file
Heavy-Light Wavefunctions in Lattice QCD
Using a multistate smearing method, Coulomb gauge wave functions of
heavy-light mesons are studied in lattice QCD. Wave functions for the ground
state, the first radially excited S-wave state, and the lowest P-wave states of
a heavy-light meson are calculated in quenched approximation. The results are
found to be in remarkably good agreement with the predictions of a simple
relativistic quark model.Comment: Latex file inputs psfig.tex, and espcrc2.sty, 3 figures in uuencoded
fil
Electromagnetic Structure of Light Baryons in Lattice QCD
A method in which electromagnetic properties of hadrons are studied by direct
simulation of dynamical photon effects is applied to the extraction of the
isomultiplet structure of the octet baryons. Using 187 configurations at
with Wilson action, and up and down quark masses determined from
the meson spectrum, the nucleon splitting is found to be MeV; the hyperon splittings are found to be
, ,
MeV. Estimated systematic corrections arising
from finite volume and the quenched approximation are included in these
results.Comment: Talk presented at LATTICE96(phenomenology
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