Improved lattice operators: Case of the topological charge density

Abstract

We analyze the properties of a class of improved lattice topological charge density operators, constructed by a smearinglike procedure. By optimizing the choice of the parameters introduced in their definition we find operators having (i) a better statistical behavior as estimators of the topological charge density on the lattice, i.e., less noisy, (ii) a multiplicative renormalization much closer to one, and (iii) a large suppression of the perturbative tail (and other unphysical mixings) in the corresponding lattice topological susceptibility.