Lattice quark masses: a non-perturbative measurement

We discuss the renormalization of different definitions of quark masses in the Wilson and the tree-level improved SW-Clover fermionic action. Using perturbative and non-perturbative renormalization constants, we study quark masses in the MS scheme from Lattice QCD in the quenched approximation at beta = 6.0, beta = 6.2 and beta = 6.4 for both actions. A reliable extrapolation to the continuum limit is however not yet possible. The most reliable results are (m) over bar(<(MS)over bar>)(2 GeV) = 5.7+/-0.1+/-0.8 MeV, m(s)(<(MS)over bar>)(2 GeV) = 130+/-2+/-18 MeV and m(c)(<(MS)over bar>) (2 GeV) = 1662+/-30+/-230 MeV.