Direct Measurement of the Hyperfine Structure of Positronium and the Decay Rate of Parapositronium using High Power Millimeter Wave
| Project/Area Number |
25800129
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Particle/Nuclear/Cosmic ray/Astro physics
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| Research Institution | The University of Tokyo |
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Principal Investigator |
YAMAZAKI Takayuki 東京大学, 素粒子物理国際研究センター, 特任研究員 (40632360)
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| Project Period (FY) |
2013-04-01 – 2015-03-31
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| Project Status |
Completed (Fiscal Year 2014)
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| Budget Amount *help |
¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000)
Fiscal Year 2014: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
Fiscal Year 2013: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
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| Keywords | 素粒子実験 / 原子・分子物理 / テラヘルツ/赤外材料・素子 / ポジトロニウム / テラヘルツ / 光源技術 |
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| Outline of Final Research Achievements |
Positronium is a bound state of an electron and a positron. The energy difference between para-positronium and ortho-positronium is called the hyperfine structure of the ground state positronium (Ps-HFS), which is caused by the spin-spin interaction between the electron and the positron. Precise measurement of Ps-HFS gives the direct information on QED in the bound state, therefore many experiments has been performed in the past. There is, however, a large discrepancy (3.9 standard deviations, 15ppm) between the measured and the theoretical value. All of the previous measurements used static magnetic field to cause Zeeman splitting to mesure Ps-HFS indirectly, and the nonuniformity of the magnetic field gives a largest systematic error. In this study, I have developed a high power (> 20kW) frequency tunable millimeter wave system and measured Ps-HFS spectroscopically for the first time. The result is published in Prog. Theor. Exp. Phys. 2015, 011C01 (2015).
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Report
(3 results)
Research Products
(12 results)
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[Presentation] Direct Measurement of Positronium Hyperfine Structure with a High-Power Millimeter-wave Gyrotron
Author(s)
A. Miyazaki, T. Yamazaki, T. Suehara, T. Namba, S. Asai, T. Kobayashi, H. Saito, Y. Tatematsu, I. Ogawa, and T. Idehara
Organizer
The 5th International Workshop on Far-Infrared Technologies (IW-FIRT2014)
Place of Presentation
Fukui, Japan
Related Report
Invited
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[Presentation] Sub-THz Spectroscopy of the Ground State Hyperfine Splitting of Positronium
Author(s)
T. Yamazaki, A. Miyazaki, T. Suehara, T. Namba, S. Asai, T. Kobayashi, H. Saito, Y. Tatematsu, I. Ogawa, and T. Idehara
Organizer
3rd Workshop on the Physics of Fundamental Symmetries and Interactions at low energies and the precision frontier (PSI2013)
Place of Presentation
Paul Scherrer Institut (PSI), Swiss Confederation
Related Report
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[Presentation] Sub-THz Spectroscopy of the Ground State Hyperfine Splitting of Positronium
Author(s)
T. Yamazaki, A. Miyazaki, T. Suehara, T. Namba, S. Asai, T. Kobayashi, H. Saito, Y. Tatematsu, I. Ogawa, and T. Idehara
Organizer
The International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz 2013)
Place of Presentation
Mainz, Germany
Related Report
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[Presentation] Direct measurement of the Hyperfine Structure of Ground-State Positronium
Author(s)
T. Namba, A. Miyazaki, T. Yamazaki, T. Suehara, S. Asai, T. Kobayashi, H. Saito, Y. Tatematsu, I. Ogawa, and T. Idehara
Organizer
The XVII International Workshop on Low-Energy Positron and Positronium Physics (POSMOL2013)
Place of Presentation
Kanazawa, Japan
Related Report
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