Form-factors and current correlators: Chiral couplings L <inf>10</inf>^r(μ) and C <inf>87</inf>^r(μ) at NLO in 1/N <inf>C</inf>

Using the resonance chiral theory Lagrangian, we perform a calculation of the vector and axial-vector two-point functions at the next-to-leading order (NLO) in the 1/N C expansion. We have analyzed these correlators within the single-resonance approximation and have also investigated the corrections induced by a second multiplet of vector and axial-vector resonance states. Imposing the correct QCD short-distance constraints, one determines the difference of the two correlators Π(t) ≡ Π VV(t)- Π AA(t) in terms of the pion decay constant and resonance masses. Its low momentum expansion fixes then the low-energy chiral couplings L 10 and C 87 at NLO, keeping full control of their renormalization scale dependence. At μ 0 = 0.77 GeV, we obtain L 10r(μ 0) = (-4.40.9)·10 -3 and C 87r(μ 0) = (3.11.1)·10 -5.