In the QCD sum rule determination of m(s) using the two-point correlat
or of divergences of Delta S = 1 vector currents, the final uncertaint
y on m(s) is mainly due to the hadronic spectral function. Using a spe
cific parameterization which fully takes into account the available ex
perimental data on the K pi (I = 1/2, J(P) = 0(+)) system, characteriz
ed by the presence of a relevant nonresonant component in addition to
the resonant one, we find (m) over bar(s)(1 GeV) greater than or equal
to 120 MeV. In particular, varying only the parameters describing the
nonresonant K pi component and Lambda nf=3/MS we obtain (m) over bar(
s)(1 GeV) = 125-160 MeV. This result is smaller than analogous ones ob
tained by using a parameterization in terms of only resonant states. W
e discuss how to systematically improve the determination of m(s) by t
his method. (C) 1997 Elsevier Science B.V.