Precision measurement of the decay rate of the negative positronium ion Ps{sup -}
- Technische Universitaet Muenchen, Lehrstuhl E21, James-Franck-Strasse 1, D-85747 Garching (Germany)
The negative positronium ion Ps{sup -} is a bound system consisting of two electrons and a positron. Its three constituents are pointlike leptonic particles of equal mass, which are subject only to the electroweak and gravitational force. Hence, Ps{sup -} is an ideal object in which to study the quantum mechanics of a three-body system. The ground state of Ps{sup -} is stable against dissociation but unstable against annihilation into photons. We report here on a precise measurement of the Ps{sup -} ground-state decay rate {Gamma}, which was carried out at the high-intensity NEutron induced POsitron source MUniCh (NEPOMUC) at the research reactor FRM II in Garching. A value of {Gamma}=2.0875(50) ns{sup -1} was obtained, which is three times more precise than previous experiments and in agreement with most recent theoretical predictions. The achieved experimental precision is at the level of the leading corrections in the theoretical predictions.
- OSTI ID:
- 22095600
- Journal Information:
- Physical Review. A, Vol. 84, Issue 6; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
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