GAMMA-DECAY INTO CHARMONIUM AND THE COLOR OCTET MECHANISM

A factorization theorem for P-wave quarkonium production, recently derived by Bodwin, Braaten, Yuan and Lepage, is applied to gamma --> (chi cJ) + X, where (chi cJ) labels the P-3(J) charmonium states. The widths for(chi cJ) production through color-singlet P-wave and color-octet S-wave c ($) over bar c subprocesses are computed each to leading order in alpha(s). Experimental data on gamma --> J/psi + X is used to obtain an upper bound on a nonperturbative parameter (related to the probability for color-octet S-wave c ($) over bar c hadronization into P-wave charmonium) that enters into the factorization theorem. The bound obtained here adds to the limited information so far available on the color-octet mechanism for P-wave quarkonium production.