Resonance saturation at next-to-leading order

TL;DR

This paper demonstrates that resonance saturation at next-to-leading order in 1/N(C) expansion holds in Resonance Chiral Theory, allowing chiral couplings to be expressed solely in terms of resonance parameters.

Contribution

It provides a detailed analysis showing that resonance saturation at NLO in 1/N(C) is consistent with QCD constraints, clarifying the dependence of chiral couplings.

Findings

Resonance saturation at NLO in 1/N(C) is satisfied.

Chiral couplings depend only on resonance masses and couplings.

Explicit dependence on chiral operator coefficients is eliminated.

Abstract

A proper estimation of the chiral low-energy constants of Chiral Perturbation Theory is a very important task. To this end resonance chiral Lagrangians have been used fruitfully. We have studied the determination of chiral couplings at next-to-leading (NLO) order in the 1/N(C) expansion, keeping full control of the renormalization scale dependence. We find that, by imposing short-distance constraints coming from QCD, resonance saturation at NLO in 1/N(C) is satisfied. In other words, the chiral couplings can be written in terms of the resonance masses and couplings and do not depend explicitly on the coefficients of the chiral operators in the Goldstone boson sector of Resonance Chiral Theory.