The strong decays of the light scalar mesons $f_0(500)$ and $f_0(980)$

TL;DR

This paper calculates the decay widths of the light scalar mesons $f_0(500)$ and $f_0(980)$ using QCD light-cone sum rules, treating them as mixtures of diquark-antidiquark states, and compares results with experimental data.

Contribution

It introduces a novel calculation of decay widths for $f_0(500)$ and $f_0(980)$ mesons using QCD sum rules with a mixture model of scalar diquark-antidiquark components.

Findings

Calculated decay widths: $434.7 ext{ MeV}$ for $f_0(500)$ and $42.12 ext{ MeV}$ for $f_0(980)$.

Results are in reasonable agreement with experimental world averages.

Supports the tetraquark mixing model for these mesons.

Abstract

The partial width of the decay channels $f_0(500) \to \pi \pi$, $f_0(980) \to \pi \pi$ and $f_0(980) \to K \bar K$ are calculated using QCD light-cone sum rules method and a technique of the soft meson approximation. The scalar particles 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. Obtained results for the full width of the $f_0(500)$ meson $\Gamma_{\mathrm{th}.}=434.7\pm 72.3~\mathrm{MeV}$ and for the $f_0(980)$ meson $\Gamma_{\mathrm{th.}}=42.12\pm 6.70~\mathrm{MeV }$ are compared with the world averages for these parameters, and a reasonable agreement between them is found.