  In this letter, we propose a novel mechanism for charmonium scattering that
utilizes the internal structure of charmonium. By capturing light flavor quarks
and anti-quarks from the vacuum, charm and anti-charm quarks form virtual
charmed mesons, which mediate an effective one-boson exchange process. This
approach accurately reproduces the di-$J/\psi$ invariant mass spectrum observed
by CMS and LHCb, demonstrating its validity. Our mechanism offers a
comprehensive framework for understanding charmonium scattering and is
applicable to the scattering problems involving all fully heavy hadrons, an
area of increasing interest.
