672 research outputs found
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
Heavy Quarkonia from Anisotropic and Isotropic Lattices
We report on recent results for the spectrum of heavy quarkonia. Using coarse
and anisotropic lattices we achieved an unprecedented control over statistical
and systematic errors for higher excited states such as exotic hybrid states.
In a parallel study on isotropic lattices we also investigate the effect of two
dynamical flavours on the spin structure of charmonium and bottomonium for
several symmetric lattices.Comment: LATTICE'99 (heavy quarks), 3 pages, 3 figure
Eta meson mass and topology in QCD with two light flavors
We present results for the mass of the flavor singlet meson calculated on
two-flavor full QCD configurations generated by the CP-PACS full QCD project.
We also investigate topological charge fluctuations and their dependence on the
sea quark mass.Comment: LATTICE99 (QCD Spectrum and Quark Masses), LaTeX(espcrc2.sty), 3
pages, 6 eps figure
Heavy-light decay constants from clover heavy quark action in QCD with two flavors of dynamical quarks
We present results on an analysis of the decay constants f_B and f_Bs with
two flavours of sea quark. The calculation has been carried out on 3 different
bare gauge couplings and 4 sea quark masses at each gauge coupling, with
m_pi/m_rho ranging from 0.8 to 0.6. We employ the Fermilab formalism to perform
calculations with heavy quarks whose mass is in the range of the b-quark. A
detailed comparison with a quenched calculation using the same action is made
to elucidate the effects due to the sea quarks.Comment: Contribution to Lattice 99 (Heavy Quarks). Latex file, uses
espcrc2.sty and epsf.sty. 3 pages, 3 encapsulated postscript figure
Equation of state in finite-temperature QCD with improved Wilson quarks
We study finite-temperature phase transition and equation of state for
two-flavor QCD at using an RG-improved gauge action and a
meanfield-improved clover quark action. The pressure is computed using the
integral method. The O(4) scaling of chiral order parameter is also examined.Comment: LATTICE99(finite temperature), 3 page
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
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
Perfect Lattice Topology: The Quantum Rotor as a Test Case
Lattice actions and topological charges that are classically and quantum
mechanically perfect (i.e. free of lattice artifacts) are constructed
analytically for the quantum rotor. It is demonstrated that the Manton action
is classically perfect while the Villain action is quantum perfect. The
geometric construction for the topological charge is only perfect at the
classical level. The quantum perfect lattice topology associates a topological
charge distribution, not just a single charge, with each lattice field
configuration. For the quantum rotor with the classically perfect action and
topological charge, the remaining cut-off effects are exponentially suppressed.Comment: 12 pages, including two figures. ordinary LaTeX, requires fps.sty;
Submitted to Phys. Lett.
I=2 Pion Scattering Length and Phase Shift with Wilson Fermions
We present preliminary results of scattering length and phase shift for I=2
S-wave system with the Wilson fermions in the quenched approximation.
The finite size method presented by L\"uscher is employed, and calculations are
carried out at on a and lattice.Comment: Lattice2001(spectrum
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