J/ψ Suppression in Nucleus-Nucleus Collisions

We propose a model for the production and suppression of J/ψ mesons in high-energy hadronic collisions. We factorized the process into a production of the cc̄ pairs of relative momentum k = kc− kc̄ convoluted with a transition probability from the produced cc̄ pairs into the observed J/ψ mesons. As the produced cc̄ pairs exit the nuclear matter, the multiple scattering between the colored c and c̄ and the nuclear medium increases the square of the relative momentum between the c and c̄, q2 = −k2, such that some of the cc̄ pairs gain enough invariant mass to transmute into open charm states. With only one parameter, the amount of energy gained by the produced cc̄ pair per unit length in the nuclear medium, our model can fit all observed J/ψ suppression data including recent NA50 data from Pb-Pb collisions. PACS: 12.38.-t, 12.38.Bx, 13.85.Ni, 14.40.Lb, 25.75.-q Typeset using REVTEX