Hadron Masses from a Novel Fat-Link Fermion Action

Hadron masses are calculated in quenched lattice QCD in order to probe the scaling behaviour of a novel fat-link clover fermion action in which only the irrelevant operators of the fermion action are constructed using APE-smeared links. Light quark masses providing a m_π/m_ρ mass ratio of 0.36 are considered to assess the exceptional configuration problem of clover-fermion actions. The simulations are performed with an order a² mean-field improved plaquette plus rectangle gluon action on a 16³ × 32 lattice with a lattice spacing of a = 0.125 fm. We compare actions with n = 4 and 12 smearing sweeps with a smearing fraction of 0.7. The n = 4 Fat Link Irrelevant Clover action provides scaling which is superior to mean-field improvement, and offers advantages over nonperturbative {O}(a) improvement including a reduced exceptional configuration problem.