TY - JOUR
T1 - Direct measurement of positronium hyperfine structure
T2 - ̃ A new horizon of precision spectroscopy using gyrotrons
AU - Asai, Shoji
AU - Yamazaki, Takayuki
AU - Miyazaki, Akira
AU - Suehara, Taikan
AU - Namba, Toshio
AU - Kobayashi, Tomio
AU - Saito, Haruhiko
AU - Idehara, Takatoshi
AU - Ogawa, Isamu
AU - Sabchevski, S.
PY - 2012/7
Y1 - 2012/7
N2 - Positronium is an ideal system for research on QED, especially in a bound state. A discrepancy (3.9s) is found recently between measured HFS values and the QED prediction (including up-to O(α 3 log α -1), where a is the fine-structure constant.). It might be due to a contribution of unknown new physics or common systematic problems in all the previous measurements. A new method to measure HFS directly is performed using a high power gyrotron. The transition from ortho-positronium to para-positronium has been observed with 5 σ CL, which is the first observation of M1 transition in (sub)Terahertz region. New technologies of high power gyrotrons are developed for precision spectroscopy.
AB - Positronium is an ideal system for research on QED, especially in a bound state. A discrepancy (3.9s) is found recently between measured HFS values and the QED prediction (including up-to O(α 3 log α -1), where a is the fine-structure constant.). It might be due to a contribution of unknown new physics or common systematic problems in all the previous measurements. A new method to measure HFS directly is performed using a high power gyrotron. The transition from ortho-positronium to para-positronium has been observed with 5 σ CL, which is the first observation of M1 transition in (sub)Terahertz region. New technologies of high power gyrotrons are developed for precision spectroscopy.
KW - Gyrotron
KW - Hyperfine splitting
KW - Positronium
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U2 - 10.1007/s10762-011-9864-8
DO - 10.1007/s10762-011-9864-8
M3 - Article
AN - SCOPUS:84863719705
SN - 1866-6892
VL - 33
SP - 766
EP - 776
JO - Journal of Infrared, Millimeter, and Terahertz Waves
JF - Journal of Infrared, Millimeter, and Terahertz Waves
IS - 7
ER -