Charm production asymmetries from heavy-quark recombination

Charm asymmetries in fixed-target hadroproduction experiments are sensitive to power corrections to the QCD factorization theorem for heavy quark production. A power correction called heavy-quark recombination has recently been proposed to explain these asymmetries. In heavy-quark recombination, a light quark or antiquark participates in a hard scattering which produces a charm-anticharm quark pair. The light quark or antiquark emerges from the scattering with small momentum in the rest frame of the charm quark, and together they hadronize into a charm particle. The cross section for this process can be calculated within perturbative QCD up to an overall normalization. Heavy-quark recombination explains the observed D meson and \Lambda_c asymmetries with a minimal set of universal nonperturbative parameters.