The structure, mixing angle, mass and couplings of the light scalar $f_0(500)$ and $f_0(980)$ mesons

TL;DR

This paper calculates the mixing angle, mass, and couplings of the light scalar mesons $f_0(500)$ and $f_0(980)$ using QCD sum rules, assuming they are tetraquark states with diquark-antidiquark structures.

Contribution

It introduces a novel QCD sum rule approach to determine the properties of $f_0(500)$ and $f_0(980)$ as tetraquarks with specific diquark-antidiquark configurations.

Findings

Determined the mixing angles $\

$f_0(500)$ and $f_0(980)$ masses and couplings.

Supported the tetraquark model for these scalar mesons.

Abstract

The mixing angle, mass and couplings of the light scalar mesons $f_0(500)$ and $f_0(980)$ are calculated in the framework of QCD two-point sum rule approach by assuming that they are tetraquarks with diquark-antidiquark structures. The mesons are treated as mixtures of the heavy $|H\rangle =([su][\bar s \bar u]+[sd][\bar s \bar d])/\sqrt 2$ and light $|L\rangle =[ud][\bar u \bar d]$ scalar diquark-antidiquark components. We extract from corresponding sum rules the mixing angles $\varphi_H$ and $\varphi_L$ of these states and evaluate the masses and couplings of the particles $ f_0(500) $ and $f_0(980)$.