Study of the hyperfine structure of antiprotonic helium

J. Sakaguchi, J. Eades, R. S. Hayano, M. Hori, D. Horváth, T. Ishikawa, B. Juhász, H. A. Torii, E. Widmann, H. Yamaguchi, T. Yamazaki

Research output: Contribution to journalConference article

5 Citations (Scopus)

Abstract

The metastable states of antiprotonic helium have a unique magnetic substructure called hyperfine structure, arising from the coupling of the large angular momentum of the antiproton (l ∼ 35) with the electron and antiproton spins. We designed, developed and performed a laser-microwave-laser resonance spectroscopy experiment to investigate this hyperfine structure. We observed two microwave transitions, and the measured frequencies agree well with recent theoretical calculations. To investigate possible collision-induced shifts of the transition frequencies, we measured the microwave transition frequencies at two different target densities. Within the limited statistics, we did not observe a clear sign of a density shift, in accordance with a theoretical estimate by Korenman. When averaging the transition frequencies over the density, we reach an agreement of about 60 ppm with the three-body QED calculations, which is of the same order than the accuracy of the calculations, and slightly larger than the experimental precision.

Original languageEnglish
Pages (from-to)89-93
Number of pages5
JournalNuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Volume214
Issue numberSUPPL.
DOIs
Publication statusPublished - Jan 1 2004
EventLow Energy Antiproton Physics (LEAP'03) - Jamashita-park, Japan
Duration: Mar 3 2003Mar 7 2003

Keywords

  • Antiprotonic helium
  • Hyperfine structure
  • Microwave spectroscopy

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Instrumentation

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    Sakaguchi, J., Eades, J., Hayano, R. S., Hori, M., Horváth, D., Ishikawa, T., Juhász, B., Torii, H. A., Widmann, E., Yamaguchi, H., & Yamazaki, T. (2004). Study of the hyperfine structure of antiprotonic helium. Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms, 214(SUPPL.), 89-93. https://doi.org/10.1016/j.nimb.2003.08.013