The direct spectroscopy of positronium hyperfine structure using a sub-THz gyrotron

Akira Miyazaki, Takayuki Yamazaki, Taikan Suehara, Toshio Namba, Shoji Asai, Tomio Kobayashi, Haruo Saito, Toshitaka Idehara, Isamu Ogawa, Yoshinori Tatematsu

Research output: Contribution to journalArticlepeer-review

30 Citations (Scopus)


Positronium is an ideal system for research on Quantum Electrodynamics (QED), especially in a bound state. A discrepancy of 3.9 standard deviations has been found between the measured hyperfine structure (Ps-HFS) and the QED predictions. This may be due to the contribution of unknown new physics or common systematic effects in previous measurements, in all of which the Zeeman effect was used. We propose a new method to directly measure the Ps-HFS using a high power gyrotron. We compare two resonators which have been developed to supply sufficient power to drive the direct transition, a Fabry-Ṕerot resonator and a ring resonator with a diffraction grating. We plan to perform first direct measurement of Ps-HFS within the next six months.

Original languageEnglish
Pages (from-to)91-100
Number of pages10
JournalJournal of Infrared, Millimeter, and Terahertz Waves
Issue number1
Publication statusPublished - Jan 2014
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Radiation
  • Instrumentation
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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