Production of $J/ψ$-pairs at HERA-$\vec{\rm N}$

Abstract

The production of $J/ψ$-pairs as a possible measure of the polarized gluon distribution $ΔG(x)$ is studied for proton--nucleon collisions at $\sqrt{s} =40\;\mbox{GeV}^2$ (HERA-$\vec{\rm N}$). Possibilities of reconstructing the helicity state of at least one of the $J/ψ$'s are critically reviewed. The observation of production asymmetries in the single polarized mode of HERA-$\vec{\rm N}$ is found to be not feasible.