Suppression ofψ′andJ/ψin High-Energy Heavy-Ion Collisions

The experimental ratio of ${\psi }^{\prime }$ to $J/\psi$ is approximately a constant in $\mathrm{pA}$ collisions, but decreases as the transverse energy increases in nucleus-nucleus collisions. These peculiar features can be explained as arising from approximately the same $c\overline{c}$-baryon absorption cross section for ${\psi }^{\prime }$ and $J/\psi$ but greater disruption probabilities for ${\psi }^{\prime }$ than for $J/\psi$ due to the interaction of the $c\overline{c}$ system with soft particles produced in baryon-baryon collisions.