  We describe a precursor in heavy quarkonium production in terms of a coherent
admixture of states of different color, spin, and angular momentum quantum
numbers, and obtain the production amplitudes for different 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 precursor with a nucleon can be calculated
with the two-gluon model of the Pomeron. Such a description of coherent
precursors and their subsequent interactions with nucleons can explain many
salient features of J/psi and psi' production in pA collisions.
