Gluon fragmentation intoP-wave heavy quarkonium

The fragmentation functions for gluons to split into P-wave heavy quarkonium states are calculated to leading order in the QCD coupling constant. Long-distance effects are factored into two nonperturbative parameters: the derivative of the radial wave function at the origin and a second parameter related to the probability for a heavy-quark--antiquark pair that is produced in a color-octet S-wave state to form a color-singlet P-wave bound state. The fragmentation probabilities for a high transverse momentum gluon to split into the P-wave charmonium states ₂₀, ₂₁, and ₂₂ are estimated to be 0. 410^-4, 1. 810^-4, and 2. 410^-4, respectively. This fragmentation process may account for a significant fraction of the rate for the inclusive production of ₂₉ at large transverse momentum in pp colliders.