Universal scale factors relating mesonic fields and quark operators

TL;DR

This paper demonstrates that scale factors linking mesonic fields and quark operators are universally constrained by chiral symmetry, providing a consistent framework that enhances understanding of scalar mesons and low-energy QCD.

Contribution

It establishes the universality of scale factors relating mesonic fields to quark operators across different scalar mesons using chiral symmetry constraints.

Findings

Confirmed universality of scale factors for different scalar mesons.

Validated the connection between chiral Lagrangians and QCD sum-rules.

Reproduced scale factors for $K_0^*$ scalars, supporting the universality hypothesis.

Abstract

Scale factor matrices relating mesonic fields in chiral Lagrangians and quark-level operators of QCD sum-rules are shown to be constrained by chiral symmetry, resulting in universal scale factors for each chiral nonet. Built upon this interplay between chiral Lagrangians and QCD sum-rules, the scale factors relating the $a_0$ isotriplet scalar mesons to their underlying quark composite field were recently determined. It is shown that the same technique when applied to $K_0^*$ isodoublet scalars reproduces the same scale factors, confirming the universality property and further validating this connection between chiral Lagrangians and QCD sum-rules which can have nontrivial impacts on our understanding of the low-energy QCD, in general, and the physics of scalar mesons in particular.