Stability of small positronic atoms in ground and excited states

Abstract

Studying the dynamical stability of positron-atom and positron-molecule complexes provides an insight into the physics and chemistry of low energy positrons and their interaction with matter. Beams of low energy positrons have applications in medical imaging (positron emission tomography) and materials science (positron annihilation spectroscopy). The first theoretical confirmation of the stability of a positronic atom (e+Li) was obtained back in 1997 [1]. However, many facts remain undiscovered. In particular, this concerns the existence of excited states.