275 research outputs found
Domain-Wall Fermions at Strong Coupling
The DWF formulation becomes increasingly problematic at gauge couplings for
which GeV, where the roughness of the gauge field leads to increased
explicit chiral symmetry breaking (\mres). This problem becomes especially
severe for sufficiently strong coupling where the underlying 4-dimensional
Wilson theory is in the Aoki phase. We review our attempts to find a suitable
modification of the gauge and/or the fermion action which would allow the DWF
method to work reliably at stronger coupling.Comment: 4 pages, 4 figures, Lattice2004(chiral
Rough Gauge Fields, Smearing and Domain Wall Fermions
At a fixed lattice spacing, as determined by say m_\rho, adding additional
fermion flavors to a dynamical simulation produces rougher gauge field
configurations at the lattice scale. For domain wall fermions, these rough
configurations lead to larger residual chiral symmetry breaking and larger
values for the residual masses, m_{res}. We discuss ongoing attempts to reduce
chiral symmetry breaking for N_f = 3 dynamical domain wall fermion simulations
by different smoothing choices for the gauge fields.Comment: 3 pages, 2 figures. Talk presented at Lattice2004(chiral), Fermilab,
June 21-26, 200
Staggered Fermion Thermodynamics using Anisotropic Lattices
Numerical simulations of full QCD on anisotropic lattices provide a
convenient way to study QCD thermodynamics with fixed physics scales and
reduced lattice spacing errors. We report results from calculations with
2-flavors of dynamical fermions where all bare parameters and hence the physics
scales are kept constant while the temperature is changed in small steps by
varying only the number of the time slices. The results from a series of
zero-temperature scale setting simulations are used to determine the Karsch
coefficients and the equation of state at finite temperatures.Comment: Lattice2002(nonzerot), 3 pages, 2 figure
Improving Dynamical Domain-Wall Fermion Simulations
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.Comment: 3 pages, 4 figures, 3 tables, Lattice2003(improve
Anisotropic Lattices and Dynamical Fermions
We report results from full QCD calculations with two flavors of dynamical
staggered fermions on anisotropic lattices. The physical anisotropy as
determined from spatial and temporal masses, their corresponding dispersion
relations, and spatial and temporal Wilson loops is studied as a function of
the bare gauge anisotropy and the bare velocity of light appearing in the Dirac
operator. The anisotropy dependence of staggered fermion flavor symmetry
breaking is also examined. These results will then be applied to the study of
2-flavor QCD thermodynamics.Comment: Lattice2001(spectrum
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