Scalar Dipion States Produced in Heavy Quarkonium Decays and the Final State Interaction

Abstract

We study phenomenologically the invariant mass spectra of scalar dipion states produced in cascade decays of excited ${\rm Y}$ and $\psi$, and $J/\psi$ decays into light vector meson. Dipion production amplitude is given as a product of the Born term and an effective scalar form factor written in terms of a unitarized chiral theory. The model reproduces the experimental mass spectra very well.

Comments: 12pages with 5 eps figs