Effects of the large gluon polarization on $xg_1^d(x)$ and J/$\psi$ productions at polarized ep and pp collisions

Abstract

The recent SMC data of $xg_1^d(x)$ are reproduced with the large polarized gluons. To study further the polarized gluon distribution in a proton, we calculate the spin--dependent differential cross section for J/$\psi$ leptoproductions and the two--spin asymmetry for J/$\psi$ hadroproductions. Its experimental implication is discussed.