Point charge versus charge distributions in ion-atom reactions

Hybrid ion-atom traps are the cornerstone of cold chemistry involving charged-neutral interactions. In these systems, a single ion is held in a time-dependent trap and exposed to a neutral gas. This leads to exciting chemical reactions such as charge exchange, radiative association, or three-body recombination. In all these reactions, it is assumed the ion is a point charge. However, the colliding partner could feel the interaction as a charge distribution since the ion is trapped. In this work, we present a theoretical study on ion-neutral collisions, considering the extension of the ground state of the ion in the trapping potential. As a result, we analyze the role of the trapping potential on the reaction dynamics. On the other hand, this system presents an interpretive dichotomy: does the neutral see a point charge in any collision, or does it feel a charge distribution? Hence, this system presents an exciting scenario for interpreting quantum mechanics.