Why the OZI rule is so strongly violated in J/Psi decays?

Abstract

The new $f_0(1790)$ meson recently observed by BES collaboration in $J/\Psi$-decay, is seen only in the OZI-forbidden channel. It is shown that chiral symmetry restoration in excited hadrons implies a new selection rule of dynamical origin that forbids some of the OZI-favoured mechanisms of decays. Hence decays into channels that are suppressed by OZI can become dominant.

Comments: 5 pages, 5 figures. The paper has been expanded. A new figure as well as implications of chiral symmetry for the search of missing a_0 mesons in charmonium decays have been added. To appear in Phys. Rev. D