QCD Sum Rules and 1/$N_c$ expansion: On the low energy dominance and separation of scattering backgrounds

TL;DR

This paper discusses how QCD sum rules combined with 1/Nc expansion can effectively separate scattering backgrounds and isolate ground state signals, demonstrated through an analysis of the sigma meson.

Contribution

It introduces a method to distinguish scattering backgrounds in multiquark correlators using 1/Nc classification, enabling clearer extraction of ground state properties.

Findings

Successful separation of scattering background and ground state in QCD sum rules

Application to sigma meson reveals its leading Nc properties

Justification of condensate factorization in multiquark analyses

Abstract

In multiquark correlator analyses with 1/Nc classifications, it is possible to separate the scattering background and to justify the factorization of condensates, which allows us to achieve an isolated peak saturation in the QCD sum rules for multiquark currents. Then we can extract leading Nc properties of the ground state. An application to the sigma meson is demonstrated.