IMPROVING THE STAGGERED QUARK ACTION TO REDUCE FLAVOR SYMMETRY VIOLATIONS

We investigate a class of actions for lattice QCD with staggered quark s aimed at reducing the flavour symmetry violations associated with us ing staggered fermions. These actions replace the gauge field link fie lds in the quark action with covariantly smeared fields. As such they are an extension of actions considered by the MILC collaboration. We s how that such actions systematically reduce flavour symmetry violation s in the weak coupling Limit. Using the mass splitting between Goldsto ne and non-Goldstone pions as a measure of flavour symmetry violations we find that these actions have considerably less flavour symmetry vi olations than the standard staggered action, and represent an improvem ent on what can be achieved with the MILC action, on quenched configur ations with beta = 5.7.