Contribution of Colour-singlet Process ${\rm Y}\to J/\Psi +c\bar{c}g$ to ${\rm Y}\to J/\Psi +X$

Abstract

We show that the colour-singlet process ${\rm Y}\to J/\Psi +c\bar{c}g$ significantly contributes to the inclusive process ${\rm Y}\to J/\Psi +X$. We calculate the partial width and the momentum distribution of the produced $J/\Psi$ in this channel. The obtained width is comparable to the experimental data. The momentum distribution is fairly soft, which is in contrast to the results from the colour-octet processes discussed earlier in literature but is consistent with the CLEO measurements. Further experiments to check this contribution are suggested.

Comments: Latex 2.0 format, 12 pages, 3 ps figures