Improved staggered quark actions with reduced flavor symmetry violations for lattice QCD

We introduce a new class of actions for staggered quarks in lattice QCD which significantly reduce flavor symmetry violations in the pion mass spectrum. An action introduced by the MILC Collaboration for the same purpose is seen to be a special case. We discuss how such actions arise from a systematic attempt to reduce flavor symmetry violations in the weak coupling limit. It is shown that for quenched lattice QCD at 6/g^2=5. 7, representative actions of this class give a considerable reduction in flavor symmetry violation over the standard staggered action, and a significant reduction over what is achieved by the MILC action.