Charm production in antiproton-nucleus collisions at the $J/ψ$ and the $ψ'$ thresholds

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 $J/ψN, ψ'N$ interaction, on the production of $Λ_c$ and $\bar{D}$ in charmonium-nucleon interactions and for the first time about 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. We extract the total $J/ψ$ nucleon cross section from photon-nucleon collisions by accounting for the color transparency phenomenon within the frame of the GVDM (Generalized Vector meson Dominance Model). We evaluate also within the GVDM the inelastic $ψ'$-nucleon cross section as well as the cross section for the nondiagonal transitions. 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.

13 pages, 10 figures, typos corrected, some discussion added