On the QCD Sum Rule Determination of the Strange Quark Mass

In the QCD Sum Rule determination of m s using the two-point correlator of divergences of \DeltaS = 1 vector currents, the final uncertainty on m s is mainly due to the hadronic spectral function. Using a specific parameterization which fully takes into account the available experimental data on the Kß (I = 1=2; J P = 0 + ) system, characterized by the presence of a relevant nonresonant component in addition to the resonant one, we find m s (1 GeV ) 120 MeV . In particular, varying only the parameters describing the nonresonant Kß component and n f =3 MS we obtain m s (1 GeV ) = 125 \Gamma 160 MeV . This result is smaller than analogous ones obtained by using a parameterization in terms of only resonant states. We discuss how to systematically improve the determination of m s by this method. Light `current' quark masses have an important role in the theoretical description of low energy hadronic physics, and their actual values are needed as an input to quantitatively pre..