Suppression of ψ' and J/ψ in high-energy heavy-ion collisions

The experimental ratio of ψ' to J/ψ is approximately a constant in 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 bar cc-baryon absorption cross section for ψ' and J/ψ but greater disruption probabilities for ψ' than for J/ψ due to the interaction of the bar cc system with soft particles produced in baryon-baryon collisions. copyright 1996 The American Physical Society