317 research outputs found
Quenched QCD with domain wall fermions
We report on simulations of quenched QCD using domain wall fermions, where we
focus on basic questions about the formalism and its ability to produce
expected low energy hadronic physics for light quarks. The work reported here
is on quenched lattices at and 5.85, using values
for the length of the fifth dimension between 10 and 48. We report results for
parameter choices which lead to the desired number of flavors, a study of
undamped modes in the extra dimension and hadron masses.Comment: Contribution to Lattice '98. Presented by R. Mawhinney. 3 pages, 3
figure
Dynamical QCD thermodynamics with domain wall fermions
We present results from numerical simulations of full, two flavor QCD
thermodynamics at N_t=4 with domain wall fermions. For the first time a
numerical simulation of the full QCD phase transition displays a low
temperature phase with spontaneous chiral symmetry breaking but intact flavor
symmetry and a high temperature phase with the full SU(2) x SU(2) chiral flavor
symmetry.Comment: LATTICE98(hightemp
The domain wall fermion chiral condensate in quenched QCD
We examine the chiral limit of domain wall fermions in quenched QCD. One
expects that in a quenched simulation, exact fermion zero modes will give a
divergent, 1/m behavior in the chiral condensate for sufficiently small valence
quark masses. Unlike other fermion formulations, domain wall fermions clearly
demonstrate this behavior.Comment: LATTICE98(spectrum), G. R. Fleming presented talk, 5 pages, 3
figures, corrected typos in printed versio
Large pion pole in Z_{S}^{MOM}/Z_{P}^{MOM} from Wilson action data
We show that, contrarily to recent claims, data from the Wilson (unimproved)
fermionic action at three different beta values demonstrate the presence of a
large Goldstone boson contribution in the quark pseudoscalar vertex,
quantitatively close to our previous estimate based on the SW action with
c_{SW}=1.769. We show that discretisation errors on Z_{S}^{MOM}/Z_{P}^{MOM}
seem to be much smaller than the Goldstone pole contribution over a very large
range of momenta. The subtraction of this non perturbative contribution leads
to numbers close to one-loop BPT.Comment: 12 pages, 5 figures, laTeX, minor corrections of typos, beta
dependence made more explicit, added one table giving the contribution of the
Goldstone vs. the discretisation errors at ap=
CLINICOIMMUNOLOGICAL PECULIARITIES OF LUNG DISEASES
Functional, bronchoscopic, microbblogbal and immunologbal peculiarities ofchronb dust bronchitis and chronic bronchitis of toxicochemica I etiology are described on the basis of studies, consisting of 144patients
Status of the QCDSP project
We describe the completed 8,192-node, 0.4Tflops machine at Columbia as well
as the 12,288-node, 0.6Tflops machine assembled at the RIKEN Brookhaven
Research Center. Present performance as well as our experience in commissioning
these large machines is presented. We outline our on-going physics program and
explain how the configuration of the machine is varied to support a wide range
of lattice QCD problems, requiring a variety of machine sizes. Finally a brief
discussion is given of future prospects for large-scale lattice QCD machines.Comment: LATTICE98(machines), 3 pages, 1 picture, 1 figur
Chirality Correlation within Dirac Eigenvectors from Domain Wall Fermions
In the dilute instanton gas model of the QCD vacuum, one expects a strong
spatial correlation between chirality and the maxima of the Dirac eigenvectors
with small eigenvalues. Following Horvath, {\it et al.} we examine this
question using lattice gauge theory within the quenched approximation. We
extend the work of those authors by using weaker coupling, , larger
lattices, , and an improved fermion formulation, domain wall fermions. In
contrast with this earlier work, we find a striking correlation between the
magnitude of the chirality density, , and the
normal density, , for the low-lying Dirac eigenvectors.Comment: latex, 25 pages including 12 eps figure
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