444 research outputs found
Theta dependence of CP^9 model
We apply to the model two recently proposed numerical techniques for
simulation of systems with a theta term. The algorithms, successfully tested in
the strong coupling limit, are applied to the weak coupling region. The results
agree and errors have been evaluated and are at % level. The results scale well
with the renormalization group equation and show that, for in presence
of a theta term, CP symmetry is spontaneously broken at in the
continuum limit.Comment: 4 pages, 4 figure
Light hadron spectrum and quark masses in QCD with two flavors of dynamical quarks
We present updated results of the CP-PACS calculation of the light hadron
spectrum in full QCD. Simulations are made with an RG-improved
gauge action and a tadpole-improved clover quark action for sea quark masses
corresponding to --0.6 and the lattice
spacing --0.09 fm. A comparison of the full QCD spectrum with new
quenched results, obtained with the same improved action, shows clearly the
existence of sea quark effects in vector meson masses. Results for light quark
masses in QCD are also presented.Comment: Latex 3 pages, 6 PostScript figures, Talk presented at LATTICE99(QCD
Spectrum and Quark Masses
Hadron masses and decay constants in quenched QCD
We present results for the mass spectrum and decay constants using
non-perturbatively O(a) improved Wilson fermions. Three values of and
30 different quark masses are used to obtain the chiral and continuum limits.
Special emphasis will be given to the question of taking the chiral limit and
the existence of non-analytic behavior predicted by quenched chiral
perturbation theory.Comment: LATTICE99(spectrum), 3 pages, 6 figure
CP-PACS Result for the Quenched Light Hadron Spectrum
The quenched hadron spectrum in the continuum obtained with the Wilson quark
action in recent simulations on the CP-PACS is presented. Results for the light
quark masses and the QCD scale parameter are reported.Comment: Talk presented by K. Kanaya at Lattice97, Edinburg
Full QCD Light Hadron Spectrum and Quark Masses: Final Results from CP-PACS
We present the final results of the CP-PACS calculation of the light hadron
spectrum and quark masses with two flavors of dynamical quarks. Simulations are
made with a renormalization-group improved gauge action and a mean-field
improved clover quark action for sea quark masses corresponding to --0.6 and the lattice spacing --0.11 fm. For
the meson spectrum in the continuum limit a clearly improved agreement with
experiment is observed compared to the quenched case, demonstrating the
importance of sea quark effects. For light quark masses we obtain
MeV and
MeV (-input) and
MeV (-input), which are reduced by
about 25% compared to the values in quenched QCD.Comment: Lattice 2000 (Spectrum), 4 pages, 3 figure
A differential correction algorithm for exponential curve fitting / CAC No. 92
Includes bibliographies
Recommended from our members
X-ray spectral line coincidences between fluorine VIII (and IX) and transition metal lines
X-ray spectroscopy was performed in the 12 to 15 A region, recording L-shell lines from selected laser-irradiated transition metals. Line coincidences and near coincidences were identified between Fe, Cr, Mn, and Ni L-spectra, and F VIII and F IX K-shell lines. Wavelengths were determined to accuracies of 1 to 3 mA and will be utilized in selecting potential pumping candidates in future x-ray lasing schemes. High-resolution x-ray spectra were collected under controlled illumination and target conditions using 1.05 ..mu..m and 0.527 ..mu..m laser excitation with the KMS CHROMA laser
Hadron spectroscopy and static quark potential in full QCD: A comparison of improved actions on the CP-PACS
We present first results from a full QCD calculation on the CP-PACS,
comparing various actions at and --0.9. We use the plaquette and a renormalization group improved action for
the gluons, and the Wilson and the SW-Clover action for quarks. We find that
significant improvements in the hadron spectrum results from improving the
quarks, while the gluon improvement is required for a rotationally invariant
static potential. An ongoing effort towards exploring the chiral limit in full
QCD is described.Comment: 6 pages, based on talks presented by R. Burkhalter and T. Kaneko at
Lattice97, Edinburg
Full QCD light hadron spectrum from the CP-PACS
We report on an on-going two-flavor full QCD study on CP-PACS using an
RG-improved gauge action and a tadpole-improved SW quark action. Runs are made
for three lattice spacings , 1.3, and 2.5 GeV on
, , and lattices. Four sea quark
masses having --0.6 are simulated, for each
of which hadron masses are evaluated for valence quark masses corresponding to
--0.5. Results for hadron and light quark
masses are presented and compared with those obtained in quenched QCD.Comment: LATTICE98(spectrum), 3 pages, 3 figure
Quenched Light Hadron Spectrum with the Wilson Quark Action: Final Results from CP-PACS
We report the final results of the CP-PACS calculation for the quenched light
hadron spectrum with the Wilson quark action. Our data support the presence of
quenched chiral singularities, and this motivates us to use mass formulae based
on quenched chiral perturbation theory in order to extrapolate hadron masses to
the physical point. Hadron masses and decay constants in the continuum limit
show unambiguous systematic deviations from experiment. We also report the
results for light quark masses.Comment: LATTICE98(spectrum). The poster at Lattice98 can be obtained from
http://www.rccp.tsukuba.ac.jp/people/yoshie/Lat98.Poster
- …