Photoproduction of charm near threshold

Charm and bottom production near threshold is sensitive to the multi-quark, gluonic, and hidden-color correlations of hadronic and nuclear wavefunctio ns in QCD since all of the target's constituents must act coherently within the small interaction volume of the heavy quark production subprocess. Alt hough such multi-parton subprocess cross sections are suppressed by powers of 1/m(Q)(2), they have less phase-space suppression and can dominate the c ontributions of the leading-twist single-gluon subprocesses in the threshol d regime. The small rates for open and hidden charm photoproduction at thre shold call for a dedicated facility. (C) 2001 Published by Elsevier Science B.V.