The yield of J/ψ and ψ’ vector-meson states has been measured for 800-GeV protons incident on deuterium, carbon, calcium, iron, and tungsten targets. A depletion of the yield per nucleon from heavy nuclei is observed for both J/ψ and ψ’ production. This depletion exhibits a strong dependence on ${\mathit{x}}_{\mathit{F}}$ and ${\mathit{p}}_{\mathit{t}}$. Within experimental errors the depletion is the same for the J/ψ and the ψ’.

• Received 31 July 1990

DOI:https://doi.org/10.1103/PhysRevLett.66.133