Decay of tripositronium to an electron and two photons

The bound state of a positron and two electrons, called tripositronium, is investigated in this article. The differential probability is calculated for the decay of the ground state of tripositronium to an electron and two photons. It is established that such a decay primarily occurs with the formation of a nonrelativistic electron. It is shown that the integral decay probability is equal to 0.15 · 10⁹ sec^–1. This corresponds to a lifetime for tripositronium of 0.65 · 10^–8 sec.Translated from Izvestiya Vysshikh Uchebnykh Zavedeoii, Fizika, No. 4, pp. 69–73, April, 1978.The author thanks V. S. Vanyashin for formulating the problem and for useful discussions.