The Relative $J/\Psi$ to $\Psi'$ Suppression in Proton-Nucleus and Nucleus-Nucleus Collisions

摘要

We calculate the nuclear suppression for $J/\Psi$ and $\Psi'$ productionwithin a coupled channel approach in the subspace of the $J/\Psi$ and $\Psi'$states. We are able to explain, why (i) the $J/\Psi$ and $\Psi'$ show the samesuppression from $200\ GeV$ to $800\ GeV$ in proton-nucleus collisions and why(ii) the $\Psi'$ is absorbed more strongly than the $J/\Psi$ in nucleus-nucleuscollisions at $200\ GeV$. The numerical result which includes only interactionswith nucleons acconts for half of the observed suppression in sulphur-uraniumcollisions.