$J/\psi$ and $\psi'$ suppression by comovers in Pb+Pb collisions
  Measurements of $\psi$ and $\psi'$ production at the CERN SPS are compared to predictions based on a hadronic model of charmonium suppression. Detailed information is presented to facilitate comparison to other analyses. Sensitivity of these conclusions to the model parameters is discussed. 
S. Gavin and R. Vogt