Observation of positronium annihilation in the 2S state: towards a new measurement of the 1S-2S transition frequency

@article{Cooke2015ObservationOP,
  title={Observation of positronium annihilation in the 2S state: towards a new measurement of the 1S-2S transition frequency},
  author={David A. Cooke and P. Crivelli and Janis Alnis and Aldo Antognini and B. Brown and Susanne Friedreich and A. Gabard and Theodor W. Haensch and K. Kirch and Andr{\'e} Rubbia and Vjeran Vrankovic},
  journal={Hyperfine Interactions},
  year={2015},
  volume={233},
  pages={67-73}
}
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… 

Figures from this paper

Producing long-lived 23S positronium via 33P laser excitation in magnetic and electric fields
Producing positronium (Ps) in the metastable $2^3\text{S}$ state is of interest for various applications in fundamental physics. We report here about an experiment in which Ps atoms are produced in
Positronium decay from n=2 states in electric and magnetic fields
We report measurements and the results of calculations demonstrating that the annihilation dynamics of positronium (Ps) atoms can be controlled by Stark and Zeeman mixing of optically excited states.
Velocity-selected production of 2S3 metastable positronium
Positronium in the $2^3S$ metastable state exhibits a low electrical polarizability and a long lifetime (1140 ns) making it a promising candidate for interferometry experiments with a neutral
Optical trapping of antihydrogen towards an atomic anti-clock
The unprecedented flux of low energy antiprotons delivered by the Extra Low ENergy Antiprotons (ELENA) ring, being under commissioning at CERN, will open a new era for precision tests with antimatter
Experimental progress in positronium laser physics
Abstract The field of experimental positronium physics has advanced significantly in the last few decades, with new areas of research driven by the development of techniques for trapping and
The Mu-MASS (muonium laser spectroscopy) experiment
We present a new experiment, Mu-MASS, aiming for a 1000-fold improvement in the determination of the 1S-2S transition frequency of Muonium (M), the positive-muon/electron bound state. This
Three-Photon-Annihilation Contributions to Positronium Energies at Order mα^{7}.
TLDR
The result for a complete class of such contributions-those involving virtual annihilation of positronium to three photons in an intermediate state are presented, finding an energy shift of 2.6216(11)mα^{7}/(nπ)^{3}=11.5/n^{3]  kHz for the spin-triplet S state with principal quantum number n.
Development of a buffer gas trap for the confinement of positrons and study of positronium production in the GBAR experiment
The GBAR experiment relies on the production of antihydrogen positive ions to achieve its goal of measuring the gravitational acceleration of antimatter at rest. The ANTION project, included in the
Collision of a Positron with the Capture of an Electron from Lithium and the Effect of a Magnetic Field on the Particles Balance
The processes of scattering slow positrons with the possible formation of positronium play an important role in the diagnosis of both composite materials, including semiconductor materials, and for
...
1
2
...

References

SHOWING 1-10 OF 24 REFERENCES
Measurement of the positronium 1(3)S1-2(3)S1 interval by continuous-wave two-photon excitation.
TLDR
The measurement of the 1-2-2 interval in positronium by Doppler-free two-photon spectroscopy is in excellent agreement with theory and sufficiently accurate to provide a test of the as-yet-uncalculated QED correction.
New precision measurement of the decay rate of singlet positronium.
TLDR
The singlet decay rate has been measured using magnetic singlet-triplet state mixing for positronium formed in a [ital N][sub 2]-isobutane gas mixture and is the first measurement sensitive enough to test the relative order [alpha][sup 2]ln[alpha] term in the singlet Decay rate calculation.
Precision Spectroscopy of Atomic Hydrogen
Precise determinations of transition frequencies of simple atomic systems are required for a number of fundamental applications such as tests of quantum electrodynamics (QED), the determination of
Measurement of the positronium 1/sup 3/S/sub 1/-2/sup 3/S/sub 1/ interval by Doppler-free two-photon spectroscopy
We have measured the 1/sup 3/S/sub 1/-2/sup 3/S/sub 1/ interval in positronium (Ps) to be 1 233 607 185 +- 15 MHz, in agreement to within 1% of the ..cap alpha../sup 3/R/sub infinity/ QED prediction.
...
1
2
3
...