Improved actions in SU(2) and SU(3) lattice gauge theories are investigated
with an emphasis on asymptotic scaling. A new scheme for tadpole improvement is
proposed. The standard but heuristic tadpole improvement emerges from a mean
field approximation from the new approach. Scaling is investigated by means of
the large distance static quark potential. Both, the generic and the new
tadpole scheme yield significant improvements on asymptotic scaling when
compared with loop improved actions. A study of the rotational symmetry
breaking terms, however, reveals that only the new improvement scheme
efficiently eliminates the leading irrelevant term from the action.Comment: minor modifications, improved presentatio