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

We show that the colour-singlet process $\mathrm{{\rm Y}}\to J\mathrm{/}\mathrm{\Psi }+c\bar{c}g$ significantly contributes to the inclusive process $\mathrm{{\rm Y}}\to J\mathrm{/}\mathrm{\Psi }+X$. We calculate the partial width and the momentum distribution of the produced $J\mathrm{/}\mathrm{\Psi }$ 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.