Instanton contributions to the low-lying hadronic mass spectrum

Abstract

The masses of the light hadrons are calculated on in lattice QCD at various stages of stout-link smearing tuned specifically to preserve instanton-like objects. The calculation is performed using a 20³ × 40 dynamical FLIC ensemble with lattice spacing 0.126 fm at a range of pion masses; the effect of vacuum instanton content is compared at a common pion mass of 350 MeV. We find little evidence that the instanton effect is as significant as models would suggest. In fact, the direct instanton-induced effect cannot be seen at all.