Getting Covariantly Smeared Sources into Better Shape
Georg M. von Hippel, Benjamin Jäger, Thomas Rae, Hartmut Wittig · Proceedings of 31st International Symposium on Lattice Field Theory LATTICE 2013 — PoS(LATTICE 2013) · 2014
The use of covariantly smeared sources in hadronic correlators is a common method of improving the projection onto the ground state.Studying the dependence of the shape of such sources on the gauge field background, we find that localized fluxes of magnetic field can strongly distort the sources.This results in a reduction of the smearing radii that can be reached by iterative smearing prescriptions, in particular as the continuum limit is approached.As a remedy, we propose a novel covariant smearing procedure ("free-form smearing") enabling the creation of arbitrarily shaped sources, including in particular Gaussians of arbitrary radius, as well as shapes with nodes, such as hydrogenic wavefunctions without the need to fix a gauge.