First determination of the strange and light quark masses from full lattice QCD

We compute the strange quark mass m(s) and the average of the u and d quark masses (m) over cap using full lattice QCD with three dynamical quarks combined with the experimental values for the pi and K masses. The simulations have degenerate u and d quarks with masses m(u)=m(d)=(m) over cap as low as m(s)/8, and two different values of the lattice spacing. The bare lattice quark masses obtained are converted to the (MS) over bar scheme using perturbation theory at O(alpha(S)). Our results are m(s)((MS) over bar)(2 GeV)=76(0)(3)(7)(0) MeV, (m) over cap ((MS) over bar)(2 GeV)=2.8(0)(1)(3)(0) MeV, and m(s)/m=27.4(1)(4)(0)(1), where the errors are from statistics, simulation, perturbation theory, and electromagnetic effects, respectively.