Double poles in Lattice QCD with mixed actions

Abstract

We consider effects resulting from the use of different discretizations for the valence and the sea quarks, considering Wilson and/or Ginsparg--Wilson fermions. We assume that such effects appear through scaling violations that can be studied using effective-lagrangian techniques. We show that a double pole is present in flavor-neutral Goldstone meson propagators, even if the flavor non-diagonal Goldstone mesons made out of valence or sea quark have equal masses. We then consider some observables known to be anomalously sensitive to the presence of a double pole. We find that the double-pole enhanced scaling violations may turn out to be rather small in practice.

8 pages; combined writeup of talks given at Lattice 2005 (Dublin) and the Workshop on Computational Hadron Physics (Cyprus)

References in corpus (5)

• Chiral Perturbation Theory for Staggered Sea Quarks and Ginsparg-Wilson Valence Quarks
• Chiral perturbation theory with Wilson-type fermions including $a^2$ effects: $N_f=2$ degenerate case
• The role of the double pole in lattice QCD with mixed actions
• Partially-Quenched Nucleon-Nucleon Scattering
• Chiral perturbation theory for lattice QCD including O(a^2)