A scaling study of the step scaling function of quenched QCD with   improved gauge actions
  We study the scaling behavior of the step scaling function for SU(3) gauge theory, employing the Iwasaki gauge action and the Luescher-Weisz gauge action. In particular, we test the choice of boundary counter terms and apply a perturbative procedure for removal of lattice artifacts for the simulation results in the extrapolation procedure. We confirm the universality of the step scaling functions at both weak and strong coupling regions. We also measure the low energy scale ratio with the Iwasaki action, and confirm its universality. 
CP-PACS Collaboration: S. Takeda, S. Aoki, M. Fukugita, K-I. Ishikawa,   N. Ishizuka, Y. Iwasaki, K. Kanaya, T. Kaneko, Y. K...