Collision Energy Dependence of Molecular Fusion and Fragmentation in ${\mathrm{C}}_{60}^{+}$ + ${\mathrm{C}}_{60}$ Collisions

Interactions between systems with a large but finite number of degrees of freedom play an important role in many branches of physics ranging from nuclear collisions to collisions between galaxies. We report the first experimental collision energy dependence of the fusion cross section for atomic cluster-cluster collisions and compare the results with quantum molecular dynamics calculations and a phenomenological fusion model. In addition, we discuss the similarities and differences to nuclear heavy ion collisions.