Peculiar features of the interaction potential between hydrogen and antihydrogen at intermediate separations

Abstract

We evaluate the interaction potential between a hydrogen and an antihydrogen using the secondorder perturbation theory within the framework of the four-body system in a separable two-body basis. We find that the H-H interaction potential possesses the peculiar features of a shallow local minimum located around interatomic separations of r ∼ 6 a.u. and a barrier rising at r 5 a.u. Additional theoretical and experimental investigations on the nature of these peculiar features will be of great interest.