| 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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