Measurement of hyperfine splitting of the ground state of muonium atom

2013 Fiscal Year Final Research Report

• Project/Area Number: 23244046
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: The University of Tokyo
• Principal Investigator: MATSUDA Yasuyuki 東京大学, 総合文化研究科, 准教授 (70321817)
• Co-Investigator(Kenkyū-buntansha): SAITO Naohito 高エネルギー加速器研究機構, 素粒子原子核研究所, 教授 (20321763) ; SHIMOMURA Koichiro 高エネルギー加速器研究機構, 物質構造科学研究所, 准教授 (60242103)
• Research Collaborator: KAWAMURA Naritoshi 高エネルギー加速器研究機構, 物質構造科学研究所, 研究機関講師 (60311338) ; SASAKI Kenichi 高エネルギー加速器研究機構, 超伝導低温工学センター, 准教授 (70322831) ; TOYOTA Akihisa 高エネルギー加速器研究機構, 素粒子原子核研究所, 助教 (20373186) ; TORII Hiroyuki 東京大学, 大学院総合文化研究科, 助教 (20302838) ; MIBE Tsutomu 大学共同利用機関法人高エネルギー加速器研究機構, 素粒子原子核研究所, 准教授 (80536938)
• Project Period (FY): 2011-04-01 – 2014-03-31
• Keywords: 素粒子（実験） / ミュオン / ミュオニウム / 超微細構造 / マイクロ波分光

Research Abstract

Muonium atom is a unique probe to verify the consistency of the standard model in very high precision and/or to investigate new physics beyond the standard model, because it is made of only leptons which do not have internal structures. We aim to realize a new experiment which aims to improve the accuracy of the measurement of hyperfine splitting of the ground state of muonium atom by an order of magnitude at J-PARC MLF. We have developed a RF cavity which has two resonance frequencies which can be independently tuned with two tuning bars, a gas chamber which holds Kr gas for three months with less than 1ppm impurity, positron detectors which can cope with high counting rate under 1T magnetic field, and a NMR system which can measure magnetic field with accuracy better than 1ppm.

Research Products

• [Journal Article] Online full two-dimentional imaging of pulsed muon beams at J-PARC MUSE using a gated image intensifier (2014)
  • Author(s): T. U. Ito, A. Toyoda, W. Higemoto, M. Tajima, Y. Matsuda, K. Shimomura
  • Journal Title: Nuclear Instruments and Methods in Physics Research A Volume: vol. 754 Pages: 1-9
  • DOI: 10.1016/j.nima.2014.04.014
  • Peer Reviewed
• [Journal Article] Development of high-rate positron tracker for the muonium production experiment at J-PARC (2014)
  • Author(s): S. Kanda, N. Saito, K. Shimomura, 他21名
  • Journal Title: JPS Conference Proceedings Volume: vol. 2 Pages: 010404-1-7
  • DOI: 10.7566/JPSCP.2.010404
  • Peer Reviewed
• [Journal Article] Measurement of muonium emission from silica aerogel (2013)
  • Author(s): P. Bakule, M. Iwasaki, S. Kanda, Y. Matsuda, N. Saito, K. Shimomura, 他25名
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: vol.2013 Pages: 103C01-103C10
  • DOI: 10.1093/ptep/ptt080
  • Peer Reviewed
• [Journal Article] J-PARC MUSE H-line optimization for the g-2 and MuHFS experiments (2013)
  • Author(s): A. Toyota, Y. Fujiwara, Y. Fukao, O. Kamigaito, N. Kawamura, Y. Matsuda T. Mibe, T. Ogitsu, N. Saito, K. Sasaki, K. Shimomura, M. Sugano, K. Tanaka, D. Tomono, H.A. Torii
  • Journal Title: Journal of Physics : Conference Series Volume: vol. 408 Pages: 012073-1-4
  • DOI: 10.1088/1742-6596/408/1/012073
  • Peer Reviewed
• [Journal Article] Superconducting Magnet Design for the Hyperfine Structure Measurement of Muonium at the J-PARC (2013)
  • Author(s): K. Sasaki, M. Sugano, R. Ohkubo, T. Ogitsu, N. Saito, K. Shimomura, A. Yamamoto
  • Journal Title: IEEE Transactions on Applied Superconductivity Volume: vol. 23 Pages: 4500704-1-4
  • DOI: 10.1109/TASC.2013.2245714
  • Peer Reviewed
• [Presentation] Precision measurement of muonium hyperfine splitting at J-PARC (2013)
  • Author(s): 神田聡太郎
  • Organizer: The 3^<rd> workshop on the Physics of Fundamental Symmetries and Interactions at low energies and the precision frontier
  • Place of Presentation: PSI 研究所、フィリンゲン、スイス
  • Year and Date: 20130909-12
• [Presentation] Status and prospect of the muonium experiment at J-PARC (2013)
  • Author(s): 鳥居寛之
  • Organizer: International Workshop on e+e- collisions from Phi to Psi
  • Place of Presentation: ローマ・ラ・サピエンツァ大学、ローマ、イタリア
  • Year and Date: 20130909-12
• [Presentation] Fundamental Physics with muon - with emphasis on muonium hyperfine interaction (2013)
  • Author(s): 松田恭幸
  • Organizer: Preschool of 1st International Symposium on Science Explored by Ultra Slow Muon
  • Place of Presentation: くにびきメッセ、島根県松江市
  • Year and Date: 20130808-12
• [Presentation] Superconducting Magnet Design for the Hyperfine Structure Measurement of Muonium at the J-PARC (2012)
  • Author(s): 佐々木賢一
  • Organizer: Applied Superconductivity Conference 2012
  • Place of Presentation: オレゴンコンベンションセンター、ポートランド、米国
  • Year and Date: 20121007-12
• [Presentation] Measurement of muonium hyperfine splitting at J-PARC (2012)
  • Author(s): 田中香津生
  • Organizer: The 23^<rd> International Conference on Atomic Physics
  • Place of Presentation: Ecole Polytechnique Palaiseau, パレゾー、フランス
  • Year and Date: 20120723-27
• [Presentation] J-PARC MUSE H-line Optimization for the g-2/EDM and MuHFS experiments (2011)
  • Author(s): 豊田晃久
  • Organizer: the 13^<th> International Workshop on Neutrino Factories, Super beams and Beta Beams
  • Place of Presentation: ジュネーブ大学、ジュネーブ、スイス
  • Year and Date: 20110801-06