Observation of positronium annihilation in the 2S state: towards a new measurement of the 1S-2S transition frequency
- Conference Paper
Rights / licenseIn Copyright - Non-Commercial Use Permitted
We report the first observation of the annihilation of positronium from the 2S state. Positronium (Ps) is excited with a two-photon transition from the 1S to the 2S state where its lifetime is increased by a factor of eight compared to the ground state due to the decrease in the overlap of the positron electron wave-function. The yield of delayed annihilation photons detected as a function of laser frequency is used as a new method of detecting laser-excited Ps in the 2S state. This can be considered the first step towards a new high precision measurement of the 1S–2S Ps line. Show more
Book titleProceedings of the International Conference on Exotic Atoms and Related Topics (EXA 2014)
Journal / seriesHyperfine Interactions
Pages / Article No.
SubjectPositronium; Spectroscopy; Bound state QED
Organisational unit03864 - Kirch, Klaus / Kirch, Klaus
03503 - Rubbia, André / Rubbia, André
NotesIt was possible to publish this article open access thanks to a Swiss National Licence with the publisher.
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