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arXiv · 1105.4352

First direct measurement of positronium hyperfine splitting with sub-THz light

T. Yamazaki·A. Miyazaki·T. Suehara·T. Namba·S. Asai·T. Kobayashi·H. Saito·Y. Urushizaki·I. Ogawa·T. Idehara·S. Sabchevski
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Abstract

Positronium is an ideal system for the research of the bound state QED. The hyperfine splitting of positronium (Ps-HFS, about 203 GHz) is an important observable but all previous measurements of Ps-HFS had been measured indirectly using Zeeman splitting. There might be the unknown systematic errors on the uniformity of magnetic field. We are trying to measure Ps-HFS directly using sub-THz radiation. We developed an optical system to accumulate high power (about 10 kW) radiation in a Fabry-P\'erot resonant cavity and observed the positronium hyperfine transition for the first time.

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T. Yamazaki, A. Miyazaki, T. Suehara, T. Namba, S. Asai, T. Kobayashi, H. Saito, Y. Urushizaki, I. Ogawa, T. Idehara, S. Sabchevski. 2011-05-22. First direct measurement of positronium hyperfine splitting with sub-THz light. https://arxiv.org/abs/1105.4352

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