Cutoff effects of heavy quark vacuum polarization at one-loop order

TL;DR

This paper investigates the impact of charm-quark vacuum polarization effects at one-loop order in lattice QCD simulations, finding that these effects are small and do not significantly affect the inclusion of charm quarks.

Contribution

The study provides a detailed one-loop analysis of charm-quark cutoff effects in lattice QCD using O(a)-improved Wilson formulation, demonstrating their minimal impact.

Findings

Charm-quark effects are small compared to gluonic effects.

Including charm-quarks in simulations is generally not problematic.

Lattice artifacts due to charm are negligible at one-loop order.

Abstract

The charm-quark mass is typically not so far from the cutoff 1/a in lattice simulations. Its determinant may then potentially introduce large cutoff effects. We choose the O(a)-improved Wilson formulation and compute the vacuum polarization effects in two rather different observables at one-loop order. One is the quark-antiquark static force and the other the Schroedinger functional coupling; in addition we investigate two more quantities resulting from the latter. In all the cases the lattice artifacts due to the charm-quark are small when compared to the gluonic effects. This indicates that the inclusion of charm-quarks in dynamical fermion simulations is typically not a problem.