The sub-THz direct spectroscopy of positronium hyperfine splitting

16th International Conference on Positron Annihilation

Miyazaki, A.^1 ; Yamazaki, T.^1 ; Suehara, T.^1 ; Namba, T.^1 ; Asai, S.^1 ; Kobayashi, T.^1 ; Saito, H.^2 ; Tatematsu, Y.^3 ; Ogawa, I.^3 ; Idehara, T.^3

Department of Physics, Graduate School of Science, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan^1

Institute of Physics, Graduate School of Arts and Sciences, University of Tokyo, 3-8-1, Komaba, Meguro-ku, Tokyo, Japan^2

Research Center for Development of Far-Infrared Region, University of Fukui (FIR-FU), 3-9-1, Bunkyo, Fukui-shi, Fukui, Japan^3

关键词: Direct measurement;    Direct transition;    Gyrotron oscillators;    Hyperfine splittings;    Hyperfine structure;    Precision measurement;    Quantum electrodynamics;    Theoretical calculations;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/443/1/012002/pdf
DOI  :  10.1088/1742-6596/443/1/012002

来源: IOP

【 摘 要 】

The positronium hyperfine splitting is a good target to study Quantum Electrodynamics in the bound state. There is a discrepancy between precision measurements and a theoretical calculation. We are planning to directly measure the positroinum hyperfine structure for the first time. A gyrotron oscillator is used as a novel radiation source in terahertz region. A Fabry-Pe´rot resonator is also developed to increase photon density. We have already observed the direct transition at 202.9 GHz. The direct measurement of the order of 100 ppm will be performed within about a year.