Paper
Color-Octet Fragmentation and the psi' Surplus at the Tevatron
Authors
Eric Braaten, Sean Fleming
Abstract
The production rate of prompt 's at large transverse momentum at the Tevatron is larger than theoretical expectations by about a factor of 30. As a solution to this puzzle, we suggest that the dominant production mechanism is the fragmentation of a gluon into a pair in a pointlike color-octet S-wave state, which subsequently evolves nonperturbatively into a plus light hadrons. The contribution to the fragmentation function from this process is enhanced by a short-distance factor of relative to the conventional color-singlet contribution. This may compensate for the suppression by , where is the relative momentum of the charm quark in the . If this is indeed the dominant production mechanism at large , then the prompt 's that are observed at the Tevatron should almost always be associated with a jet of light hadrons.