Are the J/ψ and χc A dependencies the same? Original Research Article

It has been empirically observed that the dependence of J/ψ and ψ′ production on nuclear mass number A is very similar. This has been postulated to be due to the predominance of color-octet preresonant states in charmonium production and absorption. Two new experiments, NA60 at CERN and HERA-B at DESY, will measure the χcA dependence for the first time. These measurements should shed new light on the charmonium production and absorption mechanisms.