Light hadrons with improved staggered quarks: approaching the continuum limit

TL;DR

This paper reports on advanced lattice QCD simulations using improved staggered quarks at smaller lattice spacings, providing insights into the continuum limit and light hadron spectrum with reduced discretization errors.

Contribution

The study extends previous simulations to finer lattice spacings and smaller quark masses, analyzing their effects on hadron spectrum and static quark potential with detailed systematic checks.

Findings

Reduced lattice spacing effects on hadron spectrum

Observation of decay effects in meson propagators

Preliminary results for radially excited meson masses

Abstract

We have extended our program of QCD simulations with an improved Kogut-Susskind quark action to a smaller lattice spacing, approximately 0.09 fm. Also, the simulations with a approximately 0.12 fm have been extended to smaller quark masses. In this paper we describe the new simulations and computations of the static quark potential and light hadron spectrum. These results give information about the remaining dependences on the lattice spacing. We examine the dependence of computed quantities on the spatial size of the lattice, on the numerical precision in the computations, and on the step size used in the numerical integrations. We examine the effects of autocorrelations in "simulation time" on the potential and spectrum. We see effects of decays, or coupling to two-meson states, in the 0++, 1+, and 0- meson propagators, and we make a preliminary mass computation for a radially excited 0- meson.