Confirmation of the $σ$-Meson below 1 GeV and Indication for the $f_0(1500)$ Glueball

Abstract

On the basis of a simultaneous description of the isoscalar s-wave channel of the $ππ$ scattering (from the threshold up to 1.9 GeV) and of the $ππ\to K\bar{K}$ process (from the threshold to $\sim$ 1.4 GeV) in the model-independent approach, a confirmation of the $σ$-meson at $\sim$ 660 MeV and an indication for the glueball nature of the $f_0(1500)$ state are obtained.