An improved scale parameter and Monte Carlo computations in SU(N) lattice gauge theories

We assume that scaling violation, observed for the string tension, sigma, in SU(N) lattice gauge theory with Wilson's action at N <= 3, is removed for the mixed fundamental-adjoint single-plaquette action at some negative adjoint coupling, βsub(A). We deduce then an improved scale parameter, Λsub(L), for Wilson's action using the approximate lattice universality (which becomes exact at large N). This Λsub(L) is shown to describe the scaling violation seen in the SU(3) case. We obtain Λsub(L)/√sigma approx.= 10-2 that corresponds to Λsub(mom) approx.= 340 MeV. Other dimensionful quantities do not change drastically, say, the deconfinement temperature to be 240 MeV. (orig.)