  Data on J/psi production in inelastic proton-proton, proton-nucleus and
nucleus-nucleus interactions at 158 A GeV are analyzed and it is shown that the
ratio of mean multiplicities of J/psi mesons and pions is the same for all
these collisions. This observation is difficult to understand within current
models of J/psi production in nuclear collisions based on the assumption of
hard QCD creation of charm quarks.
