Asymptotic scaling and infrared behavior of the gluon propagator - art. no. 094507

The Landau gauge gluon propagator for the pure gauge theory is evaluated on a 32(3) X 64 lattice with a physical volume of (3.35(3) X 6.7) fm(4). Comp arison with two smaller lattices at different lattice spacings allows an as sessment of finite volume and finite lattice spacing errors. Cuts on the da ta are imposed to minimize these errors. Scaling of the gluon propagator is verified between beta = 6.0 and beta = 6.2. The tensor structure is evalua ted and found to be in good agreement with the Landau gauge form, except at very small momentum values, where some small finite volume errors persist. A number of functional forms for the momentum dependence of the propagator are investigated. The form D(q(2)) = D-IR + D-UV, where D-IR(q(2)) proport ional to (q(2) + M-2)(-eta) and D-UV is an infrared regulated one-loop asym ptotic form, is found to provide an adequate description of the data over t he entire momentum region studied - thereby bridging the gap between the in frared confinement region and the ultraviolet asymptotic region. The best e stimate for the exponent eta is 3.2(-0.2-0.3)(+0.1+0.2), where the first se t of errors represents the uncertainty associated with varying the fitting range, while the second set of errors reflects the variation arising from d ifferent choices of infrared regulator in D-UV. Fixing the form of D-UV, we find that the mass parameter M is (1020 +/- 100) MeV. [S0556-2821(99)05119 -X].