Magnetically quasi-bound superpositronium states

The possibility of the existence of magnetically bound positronium states (superpositronium) is investigated starting from the two body Bethe-Salpeter equation. For the total angular momentum j=0 quasi bound energy states are found in form of resonances of the cross-section calculated with the use of the phase of the scattering states. The energies are in agreement with the observed kinetic energy of the disintegration electrons or positrons in the heavy ion collision experiments. From the width of the resonances the life-time of the quasi-bound states can be estimated. Really bound superpositronium states could not be found. (author)