Thu·Sep 18, 2003Thursday·September 18, 2003

1. 01*

   Excited States in Staggered Meson Propagators

   MILC Collaboration:C. Bernard🇺🇸 · T. Burch🇺🇸 · C. DeTar🇺🇸 · Steven Gottlieb🇺🇸 · E.B. Gregory🇺🇸 · U.M. Heller🇺🇸 · J. Osborn🇺🇸 · R. Sugar🇺🇸 · D. Toussaint🇺🇸

   We report on preliminary results from multi-particle fits to meson propagators with three flavors of light dynamical quarks. We are able to measure excited states in propagators with pion quantum numbers, which we interpret as the pion 2S state, and is evidence of locality of the action. In the a_0 (0^{++}) propagators we find evidence for excited states which are probably the expected decay channels, pi+eta and K+Kbar.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·3 citations
2. 02*

   The Phase Diagram of High Temperature QCD with Three Flavors of Improved Staggered Quarks

   The MILC Collaboration: C. Bernard🇺🇸 · T. Burch🇺🇸 · C. E. DeTar🇺🇸 · Steven Gottlieb🇺🇸 · E. B. Gregory🇺🇸 · U. M. Heller🇺🇸 · J. E. Hetrick🇺🇸 · R. L. Sugar🇺🇸 · D. Toussaint🇺🇸

   We report on progress in our study of high temperature QCD with three flavors of improved staggered quarks. Simulations are being carried out with three degenerate quarks with masses less than or equal to the strange quark mass, $m_s$, and with degenerate up and down quarks with masses in the range $0.1m_s\le m_{u,d}\le 0.6m_s$, and the strange quark mass fixed near its physical value. For the quark masses studied to date we find rapid crossovers, which sharpen as the quark mass is reduced, rather than bona fide phase transitions.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·14 citations
3. 03*

   Hybrid and Exotic Mesons from FLIC Fermions

   J. N. Hedditch🇦🇺 · D. B. Leinweber🇦🇺 · A. G. Williams🇦🇺 · J. M. Zanotti🇦🇺

   The spectral properties of hybrid meson interpolating fields are investigated. The quantum numbers of the meson are carried by smeared-source fermion operators and highly-improved chromo-electric and -magnetic field operators composed with APE-smeared links. The effective masses of standard and hybrid operators indicate that the ground state meson is effectively isolated using both standard and hybrid interpolating fields. Focus is placed on interpolating fields in which the large spinor components of the quark and antiquark fields are merged. In particular, the effective mass of the exotic $1^{-+}$ meson is reported. Further, we port some values for excited mesonic states using a variational process.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·4 citations
4. 04*

   Dirac-Kaehler fermion with noncommutative differential forms on a lattice

   I.Kanamori🇯🇵 · N.Kawamoto🇯🇵

   Noncommutativity between a differential form and a function allows us to define differential operator satisfying Leibniz's rule on a lattice. We propose a new associative Clifford product defined on the lattice by introducing the noncommutative differential forms. We show that this Clifford product naturally leads to the Dirac-Kähler fermion on the lattice.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·11 citations
5. 05*

   Heavy quark free energies, potentials and the renormalized Polyakov loop

   O. Kaczmarek🇩🇪 · F. Karsch🇩🇪 · P. Petreczky🇺🇸 · F. Zantow🇩🇪

   We discuss the renormalized free energy of a heavy quark anti-quark pair in the color singlet channel for quenched and full QCD at finite temperature. The temperature and mass dependence, as well as its short distance behavior is analyzed. Using the free energies we calculate the heavy quark potential and entropy in quenched QCD. The asymptotic large distance behavior of the free energy is used to define the non-perturbatively renormalized Polyakov loop which is well behaved in the continuum limit. String breaking is studied in the color singlet channel in 2-flavor QCD.

   hep-lathep-phNucl.Phys.B Proc.Suppl.(2004)·94 citations
6. 06*

   Improving Dynamical Domain-Wall Fermion Simulations

   L. Levkova🇺🇸 · R. Mawhinney🇺🇸

   We report on studies of the chiral properties of dynamical domain wall fermions combined with the DBW2 gauge action for different gauge couplings and fermion masses. For quenched theories, the DBW2 action gives a residual chiral symmetry breaking much smaller than what was found with more traditional choices for the gauge action. Our goal is to investigate the possibilities which this and further improvements provide for the study of QCD thermodynamics and other simulations at stronger couplings.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·5 citations
7. 07*

   Taste breaking in staggered fermions from random matrix theory

   James C. Osborn🇺🇸

   We discuss the construction of a chiral random matrix model for staggered fermions. This model includes $O(a^2)$ corrections to the continuum limit of staggered fermions and is related to the zero momentum limit of the Lee-Sharpe Lagrangian for staggered fermions. The naive construction based on a specific expansion in lattice spacing ($a$) of the Dirac matrix produces the term which gives the dominant contribution to the observed taste splitting in the pion masses. A more careful analysis can include extra terms which are also consistent with the symmetries of staggered fermions. Lastly I will mention possible uses of the model including studies of topology and fractional powers of the fermion determinant.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·14 citations
8. 08*

   Physical Baryon Resonance Spectroscopy from Lattice QCD

   D. Morel🇦🇺 · B. Crouch🇦🇺 · D.B. Leinweber🇦🇺 · A.W. Thomas🇦🇺

   We complement recent advances in the calculation of the masses of excited baryons in quenched lattice QCD with finite-range regulated chiral effective field theory enabling contact with the physical quark mass region. We examine the P-wave contributions to the low-lying nucleon and delta resonances.

   ↳ nucl-thhep-lathep-ph4 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.