Thomas, S.Kamleh, W.Leinweber, D.2017-09-142017-09-142015Physical Review D: Particles, Fields, Gravitation and Cosmology, 2015; 92(9):094515-1-094515-121550-79981550-2368http://hdl.handle.net/2440/107770Published 24 November 2015The role of instanton-like objects in the QCD vacuum on the mass spectrum of low-lying light hadrons is explored in lattice QCD. Using overimproved stout-link smearing, tuned to preserve instanton-like objects in the QCD vacuum, the evolution of the mass spectrum under smearing is examined. The calculation is performed using a 20³×40 dynamical fat-link-irrelevant-clover (FLIC) fermion action ensemble with lattice spacing 0.126 fm. Through the consideration of a range of pion masses, the effect of the vacuum instanton content is compared at a common pion mass. While the qualitative features of ground-state hadrons are preserved on instanton-dominated configurations, the excitation spectrum experiences significant changes. The underlying physics revealed shows little similarity to the direct-instanton-interaction predictions of the instanton liquid model.en© 2015 American Physical SocietyJournal article003007548710.1103/PhysRevD.92.0945150003655113000052-s2.0-84948771605369767Kamleh, W. [0000-0002-6177-5366]Leinweber, D. [0000-0002-4745-6027]