SU(3) LATENT-HEAT AND SURFACE-TENSION FROM TREE LEVEL AND TADPOLE IMPROVED ACTIONS

We analyze the latent heat and surface tension at the SU(3) deconfinem ent phase transition with tree level and tadpole improved Symanzik act ions on lattices with temporal extent N-tau = 3 and 4 and spatial exte nt N-sigma/N-tau = 4, 6 and 8. In comparison to the standard Wilson ac tion we do find a drastic reduction of cut-off effects already with tr ee level improved actions. On lattices with temporal extent N-tau = 4 results for the surface tension and latent heat obtained with a tree l evel improved action agree well with those obtained with a tadpole imp roved action. A comparison with N-tau = 3 calculations, however, shows that results obtained with tadpole action remain unaffected by cut-of f effects even on this coarse lattice, while the tree level action bec omes sensitive to the cut-off. For the surface tension and latent heat we find sigma(1)/T-c(3) = 0.0155 (16) and Delta epsilon/T-c(4) = 1.40 (9), respectively.