Positronium-ion decay

Understand

We present a precise theoretical prediction for the decay width of the bound state of two electrons and a positron (a negative positronium ion), Gamma(Ps^-) = 2.087 085(12)/ns.

• We include O(alpha^2) effects of hard virtual photons as well as soft corrections to the wave function and the decay amplitude.
• An outcome of a large-scale variational calculation, this is the first result for second-order corrections to a decay of a three-particle bound state.
• It will be tested experimentally in the new positronium-ion facility in Garching in Germany.