Color-octet fragmentation and the ψ′ sssssurplus at the fermilab tevatron

The production rate of prompt ψ′'s at large transverse momentum at the Fermilab Tevatron is larger than theoretical expectations by about a factor of 30. As a solution to this puzzle, we suggest that the dominant ψ′ production mechanism is the fragmentation of a gluon into a cc̄ pair in a pointlike color-octet S-wave state, which subsequently evolves nonperturbatively into a ψ′ plus light hadrons. This contribution to the fragmentation function is enhanced by a short-distance factor of 1/αs2, which may compensate for its suppression by v4, where v is the relative momentum of the charm quark in the ψ′.