  We study the octet SS-PP correlator within resonance chiral theory up to the
one-loop level, i.e., up to next-to-leading order in the 1/Nc expansion. We
will require that our correlator follows the power behaviour prescribed by the
operator product expansion at high euclidian momentum. Nevertheless, we will
not make use of short-distance constraints from other observables. Likewise,
the high-energy behaviour will be demanded for the whole correlator, not for
individual absorptive channels. The amplitude is progressively improved by
considering more and more complicated operators in the hadronic lagrangian.
Matching the resonance chiral theory result with chiral perturbation theory at
low energies produces the estimates L_8(mu)^{SU(3)} = (1.0+-0.4)10^-3 and
C_{38}(mu)^{SU(3)} = (8+-5) 10^-6 for mu=770 MeV. The effect of alternative
renormalization schemes is also discussed in the article.
