Antiprotonic helium

T Yamazaki, N Morita, RS Hayano, E Widmann… - Physics Reports, 2002 - Elsevier
Antiprotonic helium, a neutral three-body system p ̄ e− He 2+(= p ̄ He+), produced when
antiprotons (p ̄) are captured in various phases of helium, comprises a series of long-lived …

Forty years of antiprotons

J Eades, FJ Hartmann - Reviews of Modern Physics, 1999 - APS
The discovery of the antiproton some 40 years ago and the almost synchronous fall of parity
(P) and charge conjugation (C) symmetries were soon followed by the realization that CPT …

Antiprotonic helium and CPT invariance

RS Hayano, M Hori, D Horváth… - Reports on Progress in …, 2007 - iopscience.iop.org
We review recent progress in the laser and microwave spectroscopy of antiprotonic helium
atoms carried out at CERN's Antiproton Decelerator facility (AD). Laser transitions were here …

Sub-ppm laser spectroscopy of antiprotonic helium and a CPT-violation limit on the antiprotonic charge and mass

M Hori, J Eades, RS Hayano, T Ishikawa, J Sakaguchi… - Physical review …, 2001 - APS
Six laser-resonant transitions have been detected in metastable antiprotonic helium atoms
produced at the CERN Antiproton Decelerator. They include UV transitions from the last …

Laser measurements of the density shifts of resonance lines in antiprotonic helium atoms and stringent constraint on the antiproton charge and mass

HA Torii, RS Hayano, M Hori, T Ishikawa, N Morita… - Physical Review A, 1999 - APS
We have performed laser spectroscopy of metastable antiprotonic helium atoms (p He+)
formed in helium media of 0.2–8.0 bars at 5.8–6.3 K and have observed a density …

Antiproton magnetic moment determined from the HFS of p¯ He+

T Pask, D Barna, A Dax, RS Hayano, M Hori, D Horváth… - Physics Letters B, 2009 - Elsevier
We report a determination of the antiproton magnetic moment, measured in a three-body
system, independent of previous experiments. We present results from a systematic study of …

Hyperfine structure of antiprotonic helium energy levels

D Bakalov, VI Korobov - Physical Review A, 1998 - APS
We present a theoretical calculation of the fine and hyperfine splittings of the energy levels
in the metastable states of antiprotonic helium 4 He+ p, performed with the accuracy of 10 …

Energies and relativistic corrections for the metastable states of antiprotonic helium atoms

VI Korobov, DD Bakalov - Physical review letters, 1997 - APS
We present accurate results for the energy levels of antiprotonic helium atoms with the
relativistic and QED corrections of order α 4 mc 2 taken into account. These results reduce …

Hyperfine Structure of Antiprotonic Helium Revealed<? format?> by a Laser-Microwave-Laser Resonance Method

E Widmann, J Eades, T Ishikawa, J Sakaguchi… - Physical review …, 2002 - APS
Using a newly developed laser-microwave-laser resonance method, we observed a pair of
microwave transitions between hyperfine levels of the (n, L)=(37, 35) state of antiprotonic …

Anomalies in the decay rates of antiprotonic helium-atom states

H Yamaguchi, T Ishikawa, J Sakaguchi, E Widmann… - Physical Review A, 2002 - APS
Six resonance transitions of the antiprotonic helium atom in helium gas at densities of 3× 10
20–3× 10 21 cm− 3 were studied at the antiproton decelerator (AD) of CERN. The decay …