The static quark potential from a multilevel algorithm for the improved   gauge action
  We generalize the multilevel algorithm of Luescher and Weisz to study SU(N) Yang-Mills theories with the tree-level improved gauge action. We test this algorithm, comparing its results with those obtained using the Wilson action, in SU(3) and SU(4) Yang-Mills theories in 2+1 and 3+1 dimensions. We measure the static quark potential and extract the Luescher term, predicted by the bosonic string theory. 
Anne Mykkanen
hep-lat hep-th