We analyze the latent heat and surface tension at the SU(3) deconfinement
phase transition with tree level and tadpole improved Symanzik actions on
lattices with temporal extent Nτ=3 and 4 and spatial extent Nσ/Nτ=4, 6 and 8. In comparison to the standard Wilson action we do find a
drastic reduction of cut-off effects already with tree level improved actions.
On lattices with temporal extent Nτ=4 results for the surface tension and
latent heat obtained with a tree level improved action agree well with those
obtained with a tadpole improved action. A comparison with Nτ=3
calculations, however, shows that results obtained with tadpole action remain
unaffected by cut-off effects even on this coarse lattice, while the tree level
action becomes sensitive to the cut-off. For the surface tension and latent
heat we find σI/Tc3=0.0155(16) and Δϵ/Tc4=1.40(9), respectively.Comment: 11 pages, LaTeX2e File, 3 Postscript figure