Hard processes with spin-dependent parton distributions

To test a possible color-octet contribution of heavy quarkonium productions, we propose ψ′-productions for small-pT regions, where the color-singlet ψ′ state cannot be produced by the gluon-gluon fusion owing to charge conjugation. We also point out that these processes are very useful to deduce informations of spin-dependent gluon distributions Δg.