An Improved Action for Heavy Quarks

Abstract

We extend the Fermilab method for heavy quarks to include all interactions of dimension six in the action. We discuss a subtlety in the power counting, which implies that, for heavy quarks, certain interactions of dimension seven are commensurate with some of those of dimension six. We then present tree-level matching conditions obtained from calculating the Compton scattering amplitude for (lattice) QCD. When the matching conditions have been applied, the improved action removes (tree-level) discretization errors of order $a^2{\mathbf{p}}^3/m_Q$ and $a^3{\mathbf{p}}^3$.

Comments: 1+5 pp., contribution to Lattice 2006(Quark Masses, Gauge Couplings, and Renormalization)