Phenomenology with Wilson fermions using smeared sources

TL;DR

This study explores the impact of smeared sources on lattice QCD calculations with Wilson fermions, demonstrating improved results for hadron properties and revealing discrepancies in baryon spectra depending on source type.

Contribution

It introduces the use of non-local smeared sources in quenched lattice QCD with Wilson fermions, showing enhanced accuracy in hadron spectrum and quark property calculations.

Findings

Smeared sources significantly improve hadron mass and decay constant measurements.

Discrepancies observed between baryon spectra from different source types.

Smooth extrapolation to the chiral limit achieved with smeared sources.

Abstract

We investigate the use of two types of non-local (``smeared'') sources for quark propagators in quenched lattice QCD at $\beta=6.0$ using Wilson fermions at $\kappa=0.154$ and $0.155$. We present results for the hadron mass spectrum, meson decay constants, quark masses, the chiral condensate and the quark distribution amplitude of the pion. The use of smeared sources leads to a considerable improvement over previous results. We find a disturbing discrepancy between the baryon spectra obtained using Wuppertal and wall sources. We find good signals in the ratio of correlators used to calculate the quark mass and the chiral condensate and show that the extrapolation to the chiral limit is smooth.