  Recent BES data on $J/\psi \to \phi \pi\pi$ indicate that there is a possible
new spin-0 state ($f_0(1790)$) with a mass of $m=1790^{+40}_{-30}
\mathrm{MeV}/\mathrm{c}^2$. Assuming it to be an iso-singlet $0^+(0^{++})$, we
propose a new mixing scheme to describe this and the other three known
iso-singlet $f_0(1370)$, $f_0(1500)$, $f_0(1710)$ states by adding iso-singlet
hybrid states to the usual basis of two iso-singlet quarkonia and one glueball.
Since there are two iso-singlet hybrid states, $(u\bar u+d\bar d)g/\sqrt 2$ and
$s\bar sg$, this new basis implies existence of another iso-singlet state $X$.
Using known data, we estimate the ranges of the mixing parameters. We find two
sets of solutions with X mass predicted to be about 1820 MeV and 1760 MeV,
respectively. We also study implications on the decay properties of these new
states.
