PERFECT LATTICE ACTIONS FOR QUARKS AND GLUONS

We use perturbation theory to construct perfect lattice actions for qu arks and gluons. The renormalized trajectory for free massive quarks i s identified by blocking directly from the continuum. We tune a parame ter in the renormalization group transformation such that for Id confi gurations the perfect action reduces to the nearest-neighbor Wilson fe rmion action. The fixed point action for free gluons is also obtained by blocking from the continuum. For 2d configurations it reduces to th e standard plaquette action. Classically perfect quark and gluon field s, quark-gluon composite operators and vector and axial vector current s are constructed as well. Also the quark-antiquark potential is deriv ed from the classically perfect Polyakov loop. The quark-gluon and thr ee-gluon perfect vertex functions are determined to leading order in t he gauge coupling. This work provides a basis for the numerical constr uction of a lattice action for QCD, which is (approximately) perfect e ven beyond perturbation theory.