Quenched Light Hadron Spectroscopy: Comparing the Wilson and O(a)-Improved Fermion Actions

TL;DR

This study compares Wilson and O(a)-improved fermion actions in quenched QCD to evaluate their effects on light hadron spectra and decay constants, finding minimal differences between the two approaches within the studied mass range.

Contribution

It provides a direct comparison of Wilson and clover fermion actions in quenched QCD, highlighting their similar results for pseudoscalar meson masses and decay constants.

Findings

No significant difference in pseudoscalar meson masses between actions.

Consistent scales from string tension and mesonic sector.

Decay constant to vector meson mass ratio is quark mass independent.

Abstract

We have studied the light hadron spectrum and decay constants for quenched QCD at beta=6.2 on a 24^3x48 lattice. We compare the results obtained using a nearest-neighbour O(a)-improved ("clover") fermion action with those obtained using the standard Wilson fermion action on the same gauge configurations. For pseudoscalar meson masses in the range 330-800 MeV, we find no significant difference between the results for the two actions. The scales obtained from the string tension and mesonic sector are consistent, but higher than those derived from baryon masses. The ratio of the pseudoscalar decay constant to the vector meson mass is roughly independent of quark mass as observed experimentally.