Analysis of the scalar nonet mesons with the QCD sum rules

TL;DR

This paper investigates the nature of scalar mesons below 1 GeV by modeling them as mixed two-quark and tetraquark states, calculating their properties using advanced QCD sum rules.

Contribution

It introduces a mixed state model for scalar mesons and incorporates high-dimension condensates and alpha_s corrections in QCD sum rule calculations.

Findings

Two-quark components are dominant (>50%) in the scalar mesons.

Calculated masses and pole residues align with experimental data.

Mixing angles suggest significant tetraquark contributions.

Abstract

In this article, we assume that the nonet scalar mesons below $1\,\rm{ GeV}$ are the two-quark-tetraquark mixed states and study their masses and pole residues using the QCD sum rules. In calculation, we take into account the vacuum condensates up to dimension 10 and the $\mathcal{O}(\alpha_s)$ corrections to the perturbative terms in the operator product expansion. We determine the mixing angles, which indicate the two-quark components are much larger than $50\%$, then obtain the masses and pole residues of the nonet scalar mesons.