Light quark masses in quenched QCD with exact chiral symmetry

The parameters in the pseudoscalar meson mass formula in quenched chiral perturbation theory to one-loop order are determined by quenched lattice QCD with overlap Dirac operator, and from which the light quark masses are determined with the experimental inputs of pion and kaon masses, and the pion decay constant. Our results are mu,d=5.3±0.3 MeV, and ms=115±8 MeV, in the MS scheme at scale μ=2 GeV.