Current correlators and form factors in the resonance region

Within Resonance Chiral Theory and in the context of QCD current correlators at next-to-leading order in 1/N(C), we have analyzed the two-body form factors which include resonances as a final state . The short-distance constraints have been studied. One of the main motivations is the estimation of the chiral low-energy constants at subleading order, that is, keeping full control of the renormalization scale dependence. As an application we show the resonance estimation of some coupling, L(10)(mu_0)=(-4.4 \pm 0.9)10^{-3} and C(87)(mu_0)=(3.1 \pm 1.1)10^{-5}.