  We present the results of the current analysis of the partial wave
IJ^{PC}=00^{++} based on the available data for meson spectra (pi-pi, K\bar K,
eta-eta, eta-eta', pi-pi-pi-pi). In the framework of the K-matrix approach, the
analytical amplitude has been restored in the mass region 280 MeV< \sqrt s
<1900 MeV. The following scalar-isoscalar states are seen: comparatively narrow
resonances f_0(980), f_0(1300), f_0(1500), f_0(1750) and the broad state
f_0(1200-1600). The positions of the amplitude poles (masses and total widths
of the resonances) are determined as well as pole residues (partial widths to
meson channels pi-pi, K\bar K, eta-eta, eta-eta', pi-pi-pi-pi). The fitted
amplitude gives us the positions of the K-matrix poles (bare states) and the
values of bare-state couplings to meson channels thus allowing the
quark-antiquark nonet classification of bare states. On the basis of the
obtained partial widths to the channels pi-pi, K\bar K, eta-eta, eta-eta', we
estimate the quark/gluonium content of f_0(980), f_0(1300), f_0(1500),
f_0(1750), f_0(1200-1600). For f_0(980), f_0(1300), f_0(1500) and f_0(1750),
their partial widths testify the q\bar q origin of these mesons though being
unable to provide precise evaluation of the possible admixture of the gluonium
component in these resonances. The ratios of the decay coupling constants for
the f_0(1200-1600) support the idea about gluonium nature of this broad state.

High Energy Physics - Phenomenology