Smearing the bare quantum fields in lattice calculations before applying composite hadron creation operators has a long record of substantially improving overlaps onto low-lying energy eigenstates. A technique called distillation which defines smearing for quark fields as a low-rank linear projection operator into a small vector space of smooth gauge-covariant fields has proven to be both effective and versatile in hadron spectroscopy calculations albeit with significant computational cost . In this paper, more general operators in this space of smooth fields are introduced and optimised, which enhances the performance of the method when tested on systems of heavy quark-anti-quark pairs close to the charmonium energy scale.
Cite
@article{arxiv.2205.11564,
title = {Optimising creation operators for charmonium spectroscopy on the lattice},
author = {Francesco Knechtli and Tomasz Korzec and Michael Peardon and Juan Andrés Urrea-Niño},
journal= {arXiv preprint arXiv:2205.11564},
year = {2022}
}