${\rm Y}$ decay into charmonium and the color octet mechanism

Abstract

A factorization theorem for $P$-wave quarkonium production, recently derived by Bodwin, Braaten, Yuan and Lepage, is applied to ${\rm Y}\to {\chi }_{cJ}+X$, where ${\chi }_{cJ}$ labels the ${}^3{P}_J$ charmonium states. The widths for ${\chi }_{cJ}$ production through color-singlet $P$-wave and color-octet $S$-wave $c\bar{c}$ subprocesses are computed each to leading order in ${\alpha }_s$. Experimental data on ${\rm Y}\to J/\psi +X$ is used to obtain an upper bound on a nonperturbative parameter (related to the probability for color-octet $S$-wave $c\bar{c}$ 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.

Comments: 13 Pages (regular LaTeX document). Includes three postscript figures