Improving the staggered quark action to reduce flavor symmetry violations

摘要

The authors investigate a class of actions for lattice QCD with staggered quarks aimed at reducing the flavor symmetry violations associated with using staggered fermions. These actions replace the gauge field link fields in the quark action with covariantly smeared fields. As such they are an extension of actions considered by the MILC collaboration. They show that such actions systematically reduce flavor symmetry violations in the weak coupling limit. Using the mass splitting between Goldstone and non-Goldstone pions as a measure of flavor symmetry violations they find that these actions have considerably less flavor symmetry violations than the standard staggered action, and represent an improvement on what can be achieved with the MILC action, on quenched configurations with (beta) = 5.7.