Determination of light and strange quark masses from two-flavour dynamical lattice QCD

We compute the light and strange quark masses ml = (m(u) + m(d))/2 and m(s), respectively, in unquenched lattice QCD with N-f = 2 flavours of light dynamical quarks. The renormalisation constants, which convert bare quark masses into renormalised quark masses, are computed nonperturbatively, including the effect of quark-line disconnected diagrams. We obtain M-l(MS)(2 GeV) = 4.7(2)(3) MeV and m(s)(MS)(2 GeV) 119(5)(8) MeV, using r(0) = 0.467 fm to set the scale. (c) 2006 Elsevier B.V. All rights reserved.