J/ΨProduction,χPolarization, 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 $\sqrt{s_{\mathrm{NN}}}\approx 20\mathrm{GeV}$ at the CERN Super Proton Synchrotron (SPS) and becomes a correction at $\sqrt{s_{\mathrm{NN}}}\approx 6\mathrm{TeV}$ at the CERN Large Hadron Collider. $\mathrm{J}/\Psi$ production at the CERN SPS is well described by hard QCD, when the larger absorption cross sections of the $\chi$ states predicted by QCD are taken into account. We predict an $A$-dependent polarization of the $\chi$ states. The expansion of small wave packets is discussed.