858 research outputs found
Lattice study of nucleon properties with domain wall fermions
Domain wall fermions (DWF) are a new fermion discretization scheme with
greatly improved chiral symmetry. Our final goal is to study the nucleon spin
structure through lattice simulation using DWF. In this paper, we present our
current progress on two topics toward this goal: 1) the mass spectrum of the
nucleon excited states and 2) the iso-vector vector and axial charges,
and , of the nucleon.Comment: 8 pages, LaTeX with ws-p8-50x6-00.cls, 6 figures (6 eps files), Talk
given at NSTAR2001, University of Mainz, Germany, March 7-10, 2001. To be
published by World Scientifi
Hyperon vector coupling f_1(0) from 2+1 flavor lattice QCD
We present results for the hyperon vector form factor f_1 for and
semileptonic decays from dynamical lattice QCD with domain-wall quarks.
Simulations are performed on the 2+1 flavor gauge configurations generated by
the RBC and UKQCD Collaborations with a lattice cutoff of 1/a = 1.7 GeV. Our
preliminary results, which are calculated at the lightest sea quark mass (pion
mass down to approximately 330 MeV), show that a sign of the second-order
correction of SU(3) breaking on hyperon vector coupling f_1(0) is likely
negative.Comment: 4 pages, 2 figures, talk given at International Conference on the
Structure of Baryons (BARYONS'10), Osaka, Japan, Dec. 7-11, 201
The parity partner of the nucleon in quenched QCD with domain wall fermions
We present preliminary results for the mass spectrum of the nucleon and its
low-lying excited states from quenched lattice QCD using the domain wall
fermion method which preserves the chiral symmetry at finite lattice cutoff.
Definite mass splitting is observed between the nucleon and its parity partner.
This splitting grows with decreasing valence quark mass. We also present
preliminary data regarding the first positive-parity excited state.Comment: LATTICE99(QCD spectrum), Latex with espcrc2.sty, 3 pages, 3 figures,
RBRC preprin
Hyperon vector form factor from 2+1 flavor lattice QCD
We present the first result for the hyperon vector form factor f_1 for Xi^0
-> Sigma^+ l bar{nu} and Sigma^- -> n l bar{nu} semileptonic decays from fully
dynamical lattice QCD. The calculations are carried out with gauge
configurations generated by the RBC and UKQCD collaborations with (2+1)-flavors
of dynamical domain-wall fermions and the Iwasaki gauge action at beta=2.13,
corresponding to a cutoff 1/a=1.73 GeV. Our results, which are calculated at
the lighter three sea quark masses (the lightest pion mass down to
approximately 330 MeV), show that a sign of the second-order correction of
SU(3) breaking on the hyperon vector coupling f_1(0) is negative. The tendency
of the SU(3) breaking correction observed in this work disagrees with
predictions of both the latest baryon chiral perturbation theory result and
large N_c analysis.Comment: 7 pages, 12 figures, v2: typos corrected, and references added, v3:
version published in PR
Latest results from lattice QCD for the Roper resonance
The present status of the Roper resonance in lattice QCD is reviewed. Some of
the latest lattice results are discussed with particular emphasis on a large
systematic error stemming from the finite size effect. These results suggest
that the Roper resonance can be described by the simple three quark excitation
of sizable extent.Comment: 6 pages, 6 figures, to appear in Prog. Theor. Phys. Suppl. in the
proceedings of the Tokyo - Adelaide Joint Workshop on Quarks, Astrophysics
and Space Physics, minor typos correcte
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