A rational approximation to <VV-AA> and its O(p^6) low-energy constant

TL;DR

This paper estimates the low-energy constant C_87 in Chiral Perturbation Theory at O(p^6) using rational approximants and the large-Nc limit of QCD, providing a more precise theoretical value.

Contribution

It introduces a novel method combining rational approximants and large-Nc QCD to estimate low-energy constants in Chiral Perturbation Theory.

Findings

Estimated value of C_87 at O(p^6) in Chiral Perturbation Theory

Demonstrated effectiveness of rational approximants in QCD calculations

Provided a more accurate theoretical prediction for low-energy constants

Abstract

Using a sequence of rational approximants and the large-Nc limit of QCD, we estimate the value of the low-energy constant C_87 which appears in the Lagrangian of Chiral Perturbation Theory at O(p^6).