Chiral extrapolations with small sea quark mass data in two-flavor lattice QCD

We present results on the light hadron spectrum and quark mass in two-flavor QCD calculated with small sea quark masses down to m P S / m V = 0.35 . The configurations are generated using the RG improved gauge and tadpole-improved clover quark action at β = 1.8 , where a −1 ≃ 1 GeV . Chiral extrapolations are made using not only polynomials and ChPT in the continuum but also formulae of Wilson chiral perturbation theory (WChPT) including O ( a 2 ) chiral breaking terms. We examine the viability of WChPT and its influence on quark masses.