Quenched Light Hadron Mass Spectrum and Decay Constants: the effects of $O(a)$-Improvement at $\beta=6.2$

TL;DR

This study compares quenched QCD light hadron spectrum and decay constants using $O(a)$-improved Wilson fermions versus standard Wilson fermions at $eta=6.2$, finding minimal differences in pseudoscalar masses and consistent scale determinations.

Contribution

It demonstrates that $O(a)$-improvement has limited impact on light hadron observables at this lattice spacing in quenched QCD.

Findings

No significant difference in pseudoscalar meson masses between actions.

Consistent scales from string tension and mesonic sector.

Pseudoscalar decay constant to vector meson mass ratio increases with quark mass.

Abstract

We compare the light hadron spectrum and decay constants for quenched QCD at $\beta=6.2$ using an $O(a)$-improved nearest-neighbour Wilson fermion action with those obtained using the standard Wilson fermion action on the same set of 18 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 differ from that derived from baryon masses. The ratio of the pseudoscalar decay constant to the vector meson mass increases slowly with quark mass as observed experimentally.