HEAVY QUARKONIUM PRODUCTION AND PROPAGATION IN NUCLEI

We describe a precursor in heavy quarkonium production in terms of a c oherent admixture of states of different color, spin, and angular mome ntum quantum numbers, and obtain the production amplitudes for differe nt quarkonium bound states by projecting out this precursor state onto these bound states. The precursor is absorbed in its passage through a nucleus in a pA reaction, and the total cross section between this p recursor with a nucleon can be calculated with the two-gluon model of the Pomeron. Such a description of coherent precursors and their subse quent interactions with nucleons can explain many salient features of J/psi and psi' production in pA collisions.