  The asymmetries between charm and anticharm mesons observed in fixed-target
photoproduction experiments are an order of magnitude larger than the
asymmetries predicted by conventional perturbative QCD. We show that these
charm meson asymmetries can be explained by a heavy-quark recombination
mechanism for heavy meson production. In this process, a charm quark combines
with a light antiquark from the hard-scattering process and they subsequently
hadronize into a state including the charm meson. This recombination mechanism
can be calculated within perturbative QCD up to some nonperturbative constants.
After using symmetries of QCD to reduce the number of free parameters to two,
we obtain a good fit to all the data on the asymmetries for charmed mesons from
the E687 and E691 experiments.
