© 2015

Direct Measurement of the Hyperfine Structure Interval of Positronium Using High-Power Millimeter Wave Technology


Part of the Springer Theses book series (Springer Theses)

Table of contents

  1. Front Matter
    Pages i-xiii
  2. Akira Miyazaki
    Pages 1-16
  3. Akira Miyazaki
    Pages 17-61
  4. Akira Miyazaki
    Pages 63-85
  5. Akira Miyazaki
    Pages 87-93
  6. Akira Miyazaki
    Pages 95-96
  7. Back Matter
    Pages 97-122

About this book


In this thesis, the author develops new high-power millimeter wave techniques for measuring the hyperfine structure of positronium (Ps-HFS) directly for the first time in the world. Indirect measurement of Ps-HFS in the literature might have systematic uncertainties related to the use of a static magnetic field. Development of the millimeter wave devices supports the precise determination of Ps-HFS by directly measuring the Breit-Wigner resonant transition from o-Ps to p-Ps without the magnetic field. At the same time, the width of the measured Breit-Wigner resonance directly provides the lifetime of p-Ps. This measurement is the first precise spectroscopic experiment involving the magnetic dipole transition and high-power millimeter waves. The development of a gyrotron and a Fabry-Pérot cavity is described as providing an effective power of over 20 kW, which is required to cause the direct transition from o-Ps to p-Ps. Those values measured by the newly developed millimeter wave device pave the way for examining the discrepancy observed between conventional indirect experiments on Ps-HFS and the theoretical predictions of Quantum Electrodynamics.


Bound-state Quantum Electrodynamics Cavity Gas Neopentane Fabry-Pérot Cavity Ground States of Ps Gyrotron Hyperfine Structure of Positronium THz Gap The Breit-Wigner Resonant Transition

Authors and affiliations

  1. 1.Department of Physics, Graduate School of ScienceThe University of TokyoTokyoJapan

About the authors

Dr. Akira Miyazaki
Department of Physics, The University of Tokyo

Bibliographic information