Improved chiral properties of FLIC fermions

Abstract

The chiral properties of the fat-link irrelevant clover (FLIC) fermion action are examined. The improved chiral properties of fermion actions incorporating smoothed links are realized in the FLIC action where only the irrelevant operators of the fermion action are constructed with smoothed links. In particular, the histogram of the additive mass renormalization encountered in chiral-symmetry breaking Wilson-type fermion actions is seen to narrow upon introducing fat-links in the irrelevant operators. The exceptional configuration problem of quenched QCD is reduced, enabling access to the light quark mass regime of $m_{\pi} / m_{\rho} \sim 0.35$. In particular, quenched chiral non-analytic behavior is revealed in the light quark mass dependence of the $\Delta$-baryon mass. FLIC fermions offer a promising approach to revealing the properties of full QCD at light quark masses.