Systematics of heavy quarkonia on the basis of Regge trajectories

It is shown that, as in the case of light mesons, heavy-quarkonium states lie, to a high precision, on Regge trajectories in the (n, M ²) and (M ², J) planes with a universal slope. Specifically, \(c\bar c\) states are described to a high precision by linear trajectories. For \(b\bar b\) states, there is no such linearity but, as in the other cases, there is a universal quantum-number dependence of the trajectory.