J/Ѱ production, χ polarization, and color fluctuations

The hard contributions to the heavy quarkonium-nucleon cross sections are calculated based on the QCD factorization theorem and the nonrelativistic quarkonium model. We evaluate the nonperturbative cross sections which dominates at √^sNN≈20 GeV at the CERN Super Proton Synchrotron (SPS) and becomes a correction at √^sNN≈6 TeV at the CERN Large Hadron Collider. J/Ѱ production at the CERN SPS is well described by hard QCD, when the larger absorption cross sections of the χ states predicted by QCD are taken into account. We predict an A-dependent polarization of the χ states. The expansion of small wave packets is discussed.