The first direct measurement of the hyperfine splitting in positronium

T. Suehara, A. Ishida, T. Namba, S. Asai, T. Kobayashi, H. Saitot, M. Yoshida, T. Idehara, I. Ogawa, S. Kobayashi, S. Sabchevski

Research output: Contribution to journalConference articlepeer-review

4 Citations (Scopus)


Positronium is an ideal system for the research of the QED. The hyperfine splitting of positronium (Ps-HFS) is sensitive to the new physics beyond the Standard Model via a vacuum oscillation. Previous experimental results of the Ps-HFS show 3.5 σ discrepancy from the QED calculation, and it might be caused by uncertainties of the indirect method with static magnetic field and a few GHz RF. We developed a new direct measurement system of the Ps-HFS without static magnetic field, using a sub-THz gyrotron and a quasi-optical Fabry-Perot cavity. Status (hopefully the first result) of the direct positronium hyperfine transition observation will be presented.

Original languageEnglish
Article number152010
JournalJournal of Physics: Conference Series
Issue number15
Publication statusPublished - Dec 24 2009
Externally publishedYes
Event26th International Conference on Photonic, Electronic and Atomic Collisions - Kalamazoo, United States
Duration: Jul 22 2009Jul 28 2009

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)


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