QCD sum rule study on the $f_0(980)$ structure as a pure $K \bar{K}$ bound state

TL;DR

This study uses QCD sum rules to examine if the $f_0(980)$ meson can be modeled as a pure $Kar{K}$ bound state, concluding it likely has a more complex, mixed structure.

Contribution

The paper applies QCD sum rule analysis with operators up to dimension 10 to evaluate the $f_0(980)$ structure as a pure $Kar{K}$ bound state.

Findings

Pure $Kar{K}$ bound state description is unlikely.

$f_0(980)$ has a more complicated, mixed structure.

QCD sum rules suggest multi-component configurations.

Abstract

We perform a QCD sum rule analysis for the scalar $f_0(980)$ meson to investigate whether it can be described as a pure bound state of $K$ and $\bar{K}$ mesons. Based on the QCD sum rule with the operators of up to dimension 10 within the operator product expansion, we found that it is hard to treat the $f_0(980)$ as a simple $K\bar{K}$ bound state, which implies that the $f_0(980)$ scalar meson has more complicated structure being mixed states of various configurations.