Comparative study of the full QCD hadron spectrum and the static quark potential with improved actions -: art. no. 114508

We investigate the effects of action improvement on the light hadron spectrum and the static quark potential in two-flavor QCD for a(-1) approximate to 1 GeV and m(PS)/m(V) = 0.7-0.9. We compare a renormalization group improved action with the plaquette action for gluons and the SW-clover action with the Wilson action for quarks. We find a significant improvement in the hadron spectrum by improving the quark action, while the gluon improvement is crucial for a rotationally invariant static potential. We also explore the region of light quark masses corresponding to m(PS)/m(V) greater than or equal to 0.4 on a 2.7 fm lattice using the improved gauge and quark action. A flattening of the potential is not observed up to 2 fm. [S0556-2821(98)04721-9].