Dissociative recombination of antiprotonic atomcules p̄He+ with positronium: towards antihydrogen synthesis?

We investigate the reactive association of metastable antiprotonic helium `atomculesʹ ([p̄He+]nl) with positronium(Ps). In the framework of the Born–Oppenheimer approximation, we further discuss the evolution and stability of the intermediate complex (α, p̄, e+, 2e−) using a classical trajectory approach for treating the nuclei (α, p̄). We predict two possible channels for the atomcule–Ps reaction depending upon the atomcule principal quantum number n:n ⩾ 38 states dissociate to H̄, whereas, n<38 states form a new class of metastable atomcules, which could be confirmed by laser spectroscopy. The present work illustrates the pertinence of simple chemical physics concepts to the study of exotic processes involving antimatter.