Soft gluon emission process in the color-octet model for heavy quarkonium production - art. no. 114025

The color-octet model has been used successfully to analyze many problems i n heavy quarkonium production. We examine some of the conceptual and practi cal problems of the soft gluon emission process in the color-octet model. W e use a potential model to describe the initial and final states in the sof t gluon emission process, as the emission occurs at a late stage, after the production of the heavy quark pair. It is found in this model that the sof t gluon M1 transition S-1(0)(8)-->S-3(1)(1) dominates over the E1 transitio n P-3(J)(8)-->S-3(1)(1) for J/psi and psi' production. Such a dominance may help resolve the questions of isotropic polarization and color-octet matri x element universality in the color-octet model. [S0556-2821(99)03721-2].