The molecular Aharonov–Bohm effect redux

A solvable molecular collision model that predicts Aharonov–Bohm (AB) like scattering in the adiabatic approximation is introduced. For it, we propagate coupled channel wave packets without resorting to a Born–Oppenheimer (BO) approximation. In those, exact, solutions we find evidence of topological phase dislocation lines that are independent of the collision energy and provide definitive signatures of AB-like scattering. The results of these simulations contrast with the conclusions of a recent study that suggests survival of the molecular Aharonov–Bohm effect only in the adiabatic limit in which the nuclear reduced mass $\mu \to \infty$. We discuss generalizations of this model and consider possible screening of the Mead–Truhlar vector potential by the presence of multiple conical intersections (CI). We demonstrate that the Wilson loop phase integral has the value −1 if it encloses an odd-number of CI's, and takes the value +1 for an even number. Within the scope of this model, we investigate the ultra-cold limit of scattering solutions in the presence of a conical intersection and comment on the relevance of Wigner threshold behavior for s-wave scattering. (paper)