Noncompact gauge-invariant simulations of U(1), SU(2), and SU(3)

We have applied a new gauge-invariant, noncompact, Monte Carlo method to simulate U(1), SU(2), and SU(3) gauge theories on 84 and 124 lattices. The Creutz ratios of the Wilson loops agree with the exact results for U(1) for β≥1 apart from a renormalization of the charge. The SU(2) and SU(3) Creutz ratios robustly display quark confinement at β=0.5 and β=2, respectively. At much weaker coupling, the SU(2) and SU(3) Creutz ratios agree with perturbation theory after a renormalization of the coupling constant. For SU(3) the scaling window is near β=2, and the relation between the string tension σ and our lattice QCD parameter ΛL is √(s)∼5ΛL. ((orig.))