The structure, mixing angle, mass and couplings of the light scalar $f_0(500)$ and $f_0(980)$ 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 $|H⟩=([su][\bar{s}\bar{u}]+[sd][\bar{s}\bar{d}])/\sqrt{2}$ and light $|L⟩=[ud][\bar{u}\bar{d}]$ scalar diquark-antidiquark components. We extract from corresponding sum rules the mixing angles ${\phi }_H$ and ${\phi }_L$ of these states and evaluate the masses and couplings of the particles $f_0(500)$ and $f_0(980)$.

Comments: 6 Pages and 1 Figure. To be published in Phys. Lett. B