Polarized Gluon Distribution Function from ${\eta }^{\mathrm{\prime }}$ Production

Using the recently proposed $gg{\eta }^{\mathrm{\prime }}$ effective vertex, we investigate the production of ${\eta }^{\mathrm{\prime }}$ from gluon fusion in polarized pp collisions. We show that by measuring $A_{LL}$ in ${\eta }^{\mathrm{\prime }}$ production, one can extract the polarized gluon distribution $\mathrm{\Delta }G(x,Q^2)$ at $Q^2\sim 1{\text{GeV}}^2$ and in a wide range of x.