Probing Heavy-Quark Spin Symmetry in Double $J/\psi$ Hadroproduction

Zhi-Guo He, Xiao-Bo Jin, Bernd A. Kniehl

We perform the first complete $\mathcal{O}({\alpha }_s^5)$ analysis of the prompt hadroproduction of $J/\psi$ pairs with large transverse momenta $p_T^{\psi \psi }$ in the nonrelativistic-QCD factori…