Coulomb Artifacts and Breakdown of Perturbative Matching in Lattice NRQCD

Abstract

By studying an explicit analytical solution of the Coulomb problem on the lattice we demonstrate a breakdown of perturbative matching for the description of the Coulomb artifacts in lattice NRQCD, which leads to a large systematic error in the predictions for the heavy quarkonium spectrum. The breakdown is a result of a fine interplay between the short and long distance effects specific to the lattice regularization of NRQCD. We show how the problem can be solved within the Schrodinger matching procedure.Comment: 11 pages, 1 figure. Journal version (minor revisions implemented