Symanzik Improvement with Dynamical Charm: A 3+1 Scheme for Wilson Quarks

Abstract

We discuss the problem of lattice artefacts in QCD simulations enhanced by the introduction of dynamical charmed quarks. In particular, we advocate the use of a massive renormalization scheme with a close to realistic charm mass. To maintain O(a) improvement for Wilson type fermions in this case we define a finite size scheme and carry out a nonperturbative estimation of the clover coefficient $c_{\mathrm{sw}}$. It is summarized in a fit formula $c_{\mathrm{sw}}(g_0^2)$ that defines an improved action suitable for future dynamical charm simulations.

Comments: 17 pages, 3 tables, 2 figures, published version (extended introduction)