Detect ΔG at BNL-RHIC via double quarkonium production

The double spin asymmetry for exclusive J/ψ pair production in the polarized p–p collisions at RHIC is investigated. Our study shows that the asymmetry in this process is measurable at RHIC-Spin experiments in the near future, and, hence it can be used to determine the gluon distribution function ΔG(x) in the polarized nucleon.