Quark Loop Effects with an Improved Staggered Action

TL;DR

This paper demonstrates that an improved staggered fermion action accurately captures quark effects on hadronic observables, showing minimal quark loop effects in certain conditions and revealing modifications in the heavy quark potential and meson decay signals.

Contribution

Introduction of an improved staggered fermion action that enhances the accuracy of dynamical quark effect simulations on hadronic properties.

Findings

No significant quark loop effects in the Edinburgh plot with 2+1 flavors at a = 0.14 fm.

Dynamical quarks alter the shape of the heavy quark potential.

Evidence of meson decay effects in light hadron spectroscopy.

Abstract

We have been studying effects of dynamical quarks on various hadronic observables, using our recently formulated improvement for staggered fermions. To illustrate improvement, we show that the light hadron spectrum in the quenched approximation gives remarkably good scaling. We highlight three new results: (1) We find no apparent quark loop effects in the Edinburgh plot with 2+1 flavors of dynamical quarks at a = 0.14 fm. (2) We show that dynamical quarks modify the shape of the heavy quark potential. (3) We present results hinting at meson decay effects in light hadron spectroscopy.