Vortex States as a Novel Tool for Nuclear and Particle Physics

Vortex states of photons, electrons, and other particles are wave packets with helical wave fronts, which carry an intrinsic orbital angular momentum (OAM) projection along their average propagation direction. Such states have already been produced experimentally, albeit at low energies, and there are prospects to extend them into the MeV and GeV energy ranges. The adjustable OAM carried by such wave packets represents a completely new degree of freedom never exploited in particle and nuclear collisions. Anticipating future experimental progress, one can ask what insights into nuclei and particles may be gained once collisions of highenergy vortex states become possible. Here, we discuss the present-day situation and outline the landscape of physics opportunities offered by high-energy vortex state collisions.