We study the masses of the light quarks with lattice QCD. Most of the dependence on the lattice spacing a, observed previously with Wilson fermions, is removed by an O(a) corrected action. In the quenched approximation, we obtain a strange quark MS mass ms(2GeV)=95(16) MeV, and an average of the up and down quark masses ml(2GeV)=3.6(6) MeV. Correcting for quenching, the masses likely are 20% to 40% smaller: 54<ms(2GeV)<92 MeV and 2.1<ml(2GeV)<3.5 MeV. We argue that most lattice determinations are consistent with these low values, which are outside the range conventionally given.
ASJC Scopus subject areas
- Physics and Astronomy(all)