The nonet of the light scalar tetraquarks: the mesons $a_0(980)$ and $K_0^{\ast }(800)$

Abstract

The spectroscopic parameters and partial decay widths of the light mesons $a_0(980)$ and $K_0^{\ast }(800)$ are calculated by treating them as scalar diquark-antidiquark states. The masses and couplings of the mesons are found in the framework of QCD two-point sum rule approach. The widths of the decay channels $a_0(980)\to \hat{I}\cdot \ddot{I}€$ and $a_0(980)\to K\bar{K}$, and $K_0^{\ast }(800)\to K^{+}\ddot{I}{€}^{-}$ and $K_0^{\ast }(800)\to K^0\ddot{I}{€}^0$ are evaluated using QCD sum rules on the light-cone and technical tools of the soft meson approximation. Our results for the mass of the mesons $m_{a_0}=991_{-27}^{+29}\mathrm{MeV}$ and $m_{K^{\ast }}=767_{-29}^{+38}\mathrm{MeV}$, as well as their total width $\hat{I}{“}_{{\mathrm{a}}_0}=62.01\pm 14.37\mathrm{MeV}$ and $\hat{I}{“}_{{\mathrm{K}}_0^{\ast }}=401.1\pm 87.1\mathrm{MeV}$ are compared with last experimental data.

10 Pages and 4 Figures