3 research outputs found
Variants of fattening and flavor symmetry restoration
We study the effects of different "fat link" actions for Kogut-Susskind
quarks on flavor symmetry breaking. Our method is mostly empirical - we compute
the pion spectrum with different valence quark actions on common sets of sample
lattices. Different actions are compared, as best we can, at equivalent
physical points. We find significant reductions in flavor symmetry breaking
relative to the conventional or to the "link plus staple" actions, with a
reasonable cost in computer time. We also develop and test a scheme for
approximate unitarization of the fat links. While our tests have concentrated
on the valence quark action, our results will be useful in designing
simulations with dynamical quarks.Comment: 16 pages, LaTeX, PostScript figures include
Scaling tests of the improved Kogut-Susskind quark action
Improved lattice actions for Kogut-Susskind quarks have been shown to improve
rotational symmetry and flavor symmetry. In this work we find improved scaling
behavior of the rho and nucleon masses expressed in units of a length scale
obtained from the static quark potential, and better behavior of the Dirac
operator in instanton backgrounds.Comment: 4 pages, 4 figures, Revte