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Compelling evidence for a new form of matter has been claimed to be formed in Pb+Pb collisions at SPS. We critically review two suggested signatures for this new state of matter: First the suppression of the J/psi , which should be strongly suppressed in the QGP by two different mechanisms, the color-screening [1] and the QCD-photoe ect [2]. Secondly the measured particle, in particular strange hadronic, ratios might signal the freeze-out from a quark-gluon phase.
The statistical coalescence model for the production of open and hidden charm is considered within the canonical ensemble formulation. The data for the J/psi multiplicity in Pb+Pb collisions at 158 A·GeV are used for the model prediction of the open charm yield. We find a strong enhancement of the open charm production, by a factor of about 2 4, over the standard hard-collision model extrapolation from nucleon-nucleon to nucleus-nucleus collisions. A possible mechanism of the open charm enhancement in A+A collisions at the SPS energies is proposed.