Improvement, dynamical fermions, and heavy quark screening in QCD_3

Abstract

First results from simulations of improved actions for both gauge fields and staggered fermion fields in three dimensional QCD are presented. This work provides insight into some issues of relevance to lattice theories in four dimensions. In particular, the renormalization of the bare lattice coupling is dramatically reduced when the tree-level $O(a^2)$ improved action is used. Naik improvement of the staggered fermion action produces little reduction in scaling violations of the rho meson mass. String breaking in the heavy quark potential in the unquenched theory is also clearly resolved, using Wilson loops to bound the ground state energy.