SU(N) gauge theories in four dimensions: exploring the approach to N = infinity

We calculate the string tension, σ, and some of the lightest glueball masses, mG, in 3 + 1-dimensional SU(N) lattice gauge theories for 2 ≤ N ≤ 5. From the continuum extrapolation of the lattice values, we find that the mass ratios mG/√σ appear to show a rapid approach to the large-N limit, and, ind...