QCD on Coarse Lattices

TL;DR

This paper demonstrates that a perturbatively-improved gluon action for QCD, when tadpole-improved, yields accurate results on coarse lattices with minimal tuning, significantly reducing computational costs.

Contribution

It introduces a tadpole-improved gluon action that remains accurate on coarse lattices without coupling tuning, enabling more efficient QCD simulations.

Findings

Accurate static potential with rotational invariance within a few percent

Charmonium spectrum accurate to 30-40 MeV

Simulations on coarse lattices are much less costly

Abstract

We show that the perturbatively-improved gluon action for QCD, once it is tadpole-improved, gives accurate results even with lattice spacings as large as 0.4~fm. {\em No\/} tuning of the couplings is required. Using this action and lattice spacing, we obtain a static potential that is rotationally invariant to within a few percent, the spin-averaged charmonium spectrum accurate to within 30--40~MeV, and scaling to within 5--10\%. We demonstrate that simulations on coarse lattices are several orders of magnitude less costly than simulations using current methods.