Non-perturbative renormalization factors of bilinear quark operators for Kogut-Susskind fermions and light quark masses in quenched QCD

Abstract

Light quark masses are computed for Kogut-Susskind fermions by evaluating non-perturbatively the renormalization factor for bilinear quark operators. Calculations are carried out in the quenched approximation at β=6.0, 6.2, and 6.4. For the average up and down quark mass we find $m_{\bar{M}S}(2GeV)=4.15(27)MeV$ in the continuum limit, which is significantly larger than $3.51(20)MeV$ ($q^{\ast }=1/a$) or $3.40(21)MeV$ ($q^{\ast }=\ddot{I}€/a$) obtained with the one-loop perturbative renormalization factor.

LATTICE98(matrixelement), 3 pages, 4 eps figures