THE STRANGE QUARK MASS FROM QCD SUM-RULES

The strange quark mass is calculated from QCD sum rules for the divergence of the vector as well as axial-vector current in the next-next-to-leading logarithmic approximation. The determination for the divergence of the axial-vector current is found to be unreliable due to large uncertainties in the hadronic parametrisation of the two-point function. From the sum rule for the divergence of the Vector current, we obtain a value of m(s) = ($) over bar m(s)(1 GeV) = 189 +/- 32 MeV, where the error is dominated by the unknown perturbative O(alpha(s)(3)) correction. Assuming a continued geometric growth of the perturbation series, we find m(s) = 178 +/- 18 MeV. Using both determinations of m(s), together with quark-mass ratios from chiral perturbation theory, we also give estimates of the light quark masses m(u) and m(d).