Chiral corrections for lattice QCD

Abstract

We show that in the quenched approximation, lattice QCD calculations miss important corrections to the mass of hadrons. For example, we argue that the nucleon mass is overestimated by up to 30% while the nucleon-delta mass splitting is underestimated by a similar amount. As the quenched approximation is relaxed, the quark mass decreased and the lattice size increased, these errors should go away. A systematic method of monitoring the size of the residual error is suggested.