Charm Production in $\bar pA$-Collisions at the Charmonium Threshhold

Abstract

We discuss the production of charmonium states in antiproton-nucleus collisions at the $ψ'$ threshold. It is explained that measurements in $\bar p A$ collisions will allow to get new information about the strengths of the inelastic $J/ψN$ and $ψ'N$ interaction, on the production of $Λ_c$ and $\bar{D}$ in charmonium-nucleon interactions and for the first time about the nondiagonal transitions $ψ' N\to J/ψN$. The inelastic $J/ψ$-nucleon cross section is extracted from the comparison of hadron-nucleus collisions with hadron-nucleon collisions. Predictions for the ratio of $J/ψ$ to $ψ'$ yields in antiproton-nucleus scatterings close to the threshold of $ψ'$ production for different nuclear targets are presented.