Light and Strange Quark Masses with Dynamical Wilson Fermions

We determine the masses of the light and the strange quarks in the MS-bar-scheme using our high-statistics lattice simulation of QCD with dynamical Wilson fermions. For each of our three sea quarks we have analyzed our data at five different values of the valence quark mass, enabling us to parameterize our fit results in the (sea-quark mass, valence quark mass) plane. For the light quark mass we find m_light(2 GeV) = 2.7(2) MeV, which is lower than in quenched simulations. Applying a new method, which we propose to extract the strange quark mass in a sea of two dynamical light quarks, we obtain m_strange(2 GeV) = 140(20) MeV.