Measurement of the annihilation decay rate of 2 3 S 1 positronium
R. E. Sheldon, Tamara J. Babij, Brendan Devlin-Hill +2 more
We report a measurement of the annihilation decay rate of positronium (Ps) atoms, . Ground state atoms optically excited to radiatively metastable states were quenched via Stark mixing by the application of a time-delayed electric field. Rapid radiative decay of the Stark mixed states to the ground state, followed by self-annihilation, was observed via the annihilation radiation time spectrum, and used to determine the number of excited state atoms remaining at different times, and hence the decay rate. We obtain , in broad agreement with the Zeeman-shifted theoretical value of .
Europhysics Letters (EPL)•Nov 3, 2020•3 citations