Cross Sections for the Dissociation of J/psi and psi' by pi and rho at low energies

Abstract

Using the quark-interchange model of Barnes and Swanson, we evaluate the dissociation cross sections for $J/\psi$ and ${\psi }^{\prime }$ by $\pi$ and $\rho$ at low collision energies. In collisions with $\pi$ mesons near threshold the $\pi +J/\psi$ dissociation cross section is predicted to be small, but the $\pi +{\psi }^{\prime }$ cross section is found to be quite large, in qualitative agreement with experimental data on $J/\psi$ and ${\psi }^{\prime }$ production in high-energy heavy-ion collisions. The $\rho +J/\psi$ and $\rho +{\psi }^{\prime }$ dissociation cross sections are both predicted to be large numerically and are divergent near threshold. These $\rho +J/\psi$ and $\rho +{\psi }^{\prime }$ cross sections show considerable sensitivity to the mass of the $\rho$ meson if it is off energy shell.

Comments: Invited Talk presented at Hirsch 2000 Workshop, Austria, Hadrons in Dense Matter, 16-22 January 2000, Hirschegg, Austria