Two-Photon Total Annihilation of Molecular Positronium

Abstract

The rate for complete two-photon annihilation of molecular positronium Ps${}_2$ is reported. This decay channel involves a four-body collision among the fermions forming Ps${}_2$, and two photons of 1.022 MeV, each, as the final state. The quantum electrodynamics result for the rate of this process is found to be ${\Gamma }_{P{s}_2\to \gamma \gamma }$ = 9.0 $\times 10^{-12}$ s${}^{-1}$. This decay channel completes the most comprehensive decay chart for Ps${}_2$ up to date.

Comments: 4 pages, 2figures and 1 table