Precise Measurement of Positronium Hyperfine Splitting (Ps-HFS)

Measurement of the energy level difference between orthopositronium and parapositronium (0.84 meV) at a precision of O(ppm).

Publications, etc.

Akira Ishida, "New Precision Measurement of Hyperfine Splitting of Positronium", Def. Diff. Forum 373, 75 (2017).
A Ishida, T Namba and S Asai, "Measurement of positronium thermalization in isobutane gas for precision measurement of ground-state hyperfine splitting", J. Phys. B: At. Mol. Opt. Phys. 49 (2016) 064008 (6pp).
A. Ishida, "New Precise Measurement of the Hyperfine Splitting of Positronium", J. Phys. Chem. Ref. Data 44, 031212 (2015).
A. Ishida, "New precise measurement of the hyperfine splitting of positronium", Positron Sciences 4, 35-42 (2015).
A. Ishida, T. Namba, S. Asai, T. Kobayashi, H. Saito, M. Yoshida, K. Tanaka, A. Yamamoto, "New Precision Measurement of Hyperfine Splitting of Positronium", Phys. Lett. B 734 (2014) 338-344 (arXiv:1310.6923 (2013)).
A. Ishida, Y. Sasaki, G. Akimoto, T. Suehara, T. Namba, S. Asai, T. Kobayashi, H. Saito, M. Yoshida, K. Tanaka, A. Yamamoto, "Precise measurement of positronium hyperfine splitting using the Zeeman effect", Hyperfine Interact. 212, 133 (2012) (arXiv:1105.4392 (2011)).
Y. Sasaki, A. Miyazaki, A. Ishida, T. Namba, S. Asai, T. Kobayashi, H. Saito, K. Tanaka, A. Yamamoto, "Measurement of positronium hyperfine splitting with quantum oscillation", Phys. Lett. B 697, pp. 121-126 (2011).
A. Ishida, G. Akimoto, Y. Sasaki, T. Suehara, T. Namba, S. Asai, T. Kobayashi, H. Saito, M. Yoshida, K. Tanaka, and A. Yamamoto, "Precise Measurement of Hyperfine Splitting of Positronium Using the Zeeman Effect", Materials Science Forum Vol. 666, pp. 129-132 (2011).
T. Namba, A. Ishida, and G. Akimoto, "Precise Measurement of Hyperfine Structure of Positronium(Current Topics)"、日本物理学会誌 Vol. 65, No. 10, pp. 810-813 (2010).
A. Ishida, G. Akimoto, Y. Sasaki, T. Suehara, T. Namba, S. Asai, T. Kobayashi, H. Saito, M. Yoshida, K. Tanaka, and A. Yamamoto, "New method of precise measurement of positronium hyperfine splitting", arXiv:1004.5555 (2010).
A. Ishida, G. Akimoto, Y. Sasaki, A. Miyazaki, K. Kato, T. Suehara, T. Namba, S. Asai, T. Kobayashi, H. Saito, M. Yoshida, K. Tanaka, A. Yamamoto, Y. Urushizaki, I. Ogawa, T. Idehara and S. Sabchevski, "Precise measurement of HFS of positronium using Zeeman effect", J. Phys.: Conf. Ser. 225 012019 (2010)
A. Ishida, G. Akimoto, K. Kato, T. Suehara, T. Namba, S. Asai, T. Kobayashi, H. Saito, M. Yoshida, K. Tanaka, A. Yamamoto, I. Ogawa, S. Kobayashi and T. Idehara, "Precise measurement of HFS of positronium", J. Phys.: Conf. Ser. 199 012004 (2010). (arXiv:0912.4370, (2009))

Thesis

A. Ishida, "New precise measurement of the hyperfine splitting of positronium", PhD thesis, the University of Tokyo, 2014. English(pdf)
A. Ishida, "Precise Measurement of HFS of Positronium", Master thesis, the University of Tokyo, 2010 (JFY 2009). Japanese(pdf)

Presentations and Posters

"Precision measurement of the hyperfine splitting of positronium" (A. Ishida, International Conference on Precision Physics and Fundamental Physical Constants (FFK-2015), 12 Oct 2015, Budapest, Hungary) (Invited) English, go to FFK-2015 Indico time table
"New precision measurement of hyperfine splitting of positronium" (A. Ishida, The 17th International Conference on Positron Annihilation (ICPA-17), 21 Sep 2015, Wuhan, China) English(pdf)
"New Measurements of the Positronium Hyperfine Splitting" (A. Ishida, The XVIII International Workshop on Low-Energy Positron and Positronium Physics (POSMOL 2015), 19 Jul 2015, Lisboa, Portugal) (Invited) English(pdf)
"New precise measurement of the hyperfine splitting of positronium"(Poster) (A. Ishida, The XVIII International Workshop on Low-Energy Positron and Positronium Physics (POSMOL 2015), Jul 2015, Lisboa, Portugal) English(pdf)
"New Precision Measurement of the Hyperfine Splitting of Positronium" (A. Ishida, DESY Physics Seminar, 22 Apr 2015, Zeuthen, Germany) English(pdf)
"New Precision Measurement of the Hyperfine Splitting of Positronium" (A. Ishida, DESY Physics Seminar, 21 Apr 2015, Hamburg, Germany) English(pdf)
"New precise measurement of the hyperfine splitting of positronium" (A. Ishida, Fundamental Constants Meeting 2015, 06 Feb 2015, Eltville, Germany) (Invited) English(pdf)
"Precision Measurement of Positronium Hyperfine Splitting" (A. Ishida, JPS 2013 autumn meeting, 20 Sep 2013, Kochi University, Kochi, Japan) Japanese(pdf)
"New precision measurement of Hyperfine Splitting of Positronium"(Poster) (A. Ishida, The XVII International Workshop on Low-Energy Positron and Positronium Physics (POSMOL2013), July 2013, Kanazawa, Japan) English(pdf)
"Precision measurement of Positronium Hyperfine Splitting" (A. Ishida, JPS 68th annual meeting, 27 Mar 2013, Hiroshima University, Higashi Hiroshima, Hiroshima, Japan) Japanese(pdf)
"Precision measurement of Positronium Hyperfine Splitting" (A. Ishida, Kyoto University Research Reactor Institute Special Workshop "Positron Science and its Application to Science and Technology", 30 Nov 2012, Kyoto University Research Reactor Institute, Osaka, Japan) Japanese(pdf)
"Precision Measurement of Positronium Hyperfine Splitting" (A. Ishida, JPS 2012 autumn meeting, 11 Sep 2012, Kyoto Sangyo University, Kyoto, Japan) Japanese(pdf)
"Precision Measurement of Positronium Hyperfine Splitting" (A. Ishida, The 49th Annual Meeting on Radioisotope and Radiation Research, 10 Jul 2012, The University of Tokyo Yayoi Auditorium, Tokyo, Japan) Japanese(pdf)
"Precision Measurement of Positronium Hyperfine Splitting using the Zeeman effect" (A. Ishida, JPS 67th annual meeting, 24 Mar 2012, Kwansei Gakuin University, Nishinomiya, Hyogo, Japan) Japanese(pdf)
"Precision Measurement of Positronium Hyperfine Splitting" (A. Ishida, 18th ICEPP Symposium, 21 Feb 2012, Nagano, Japan) Japanese(pdf)
"Precision measurement of Positronium Hyperfine Splitting" (A. Ishida, Kyoto University Research Reactor Institute Special Workshop "Positron Science and its Application to Science and Technology", 3 Dec 2011, Kyoto University Research Reactor Institute, Osaka, Japan) Japanese(pdf)
"Precision measurement of positronium hyperfine splitting using the Zeeman effect" (A. Ishida, Cold Antimatter and High Precision Physics (Pbar11), 28 Nov 2011, Kunibiki-Messe, Matsue, Shimane, Japan) English(pdf)
"Precision measurement of positronium hyperfine splitting using the Zeeman effect" (A. Ishida, KEK Cryogenics Science Center Sminar, 20 Oct 2011, KEK, Ibaraki, Japan) Japanese(pdf)
"Precise measurement of positronium hyperfine splitting using the Zeeman effect" (A. Ishida, Fundamental Physics Using Atoms (FPUA) 2011, 8 Oct 2011, Okayama University, Okayama, Japan)English(pdf)
"Precise Measurement of Positronium Hyperfine Splitting using the Zeeman effect" (A. Ishida, JPS 2011 autumn meeting, 18 Sep 2011, Hirosaki University, Hirosaki, Aomori, Japan) Japanese(pdf)
"Precise Measurement of Positronium Hyperfine Splitting" (A. Ishida, 12 Jul 2011, Komaba, Tokyo, Japan) Japanese(pdf)
"Precise Measurement of Positronium Hyperfine Splitting" (A. Ishida, The 48th Annual Meeting on Radioisotope and Radiation Research, 8 Jul 2011, National Museum of Emerging Science and Innovation, Tokyo, Japan) Japanese(pdf)
"Precise measurement of positronium hyperfine splitting using the Zeeman effect" (A. Ishida, 10th International Conference on Low Energy Antiproton Physics (LEAP 2011), 28 Apr 2011, TRIUMF, Vancouver, Canada)English(pdf) (Proceeding)
"Precise Measurement of Positronium Hyperfine Splitting using the Zeeman Effect" (A. Ishida, JPS 66th annual meeting, 27 Mar 2011, Nigata, Japan (みなし発表))Japanese(pdf)
"Precise Measurement of Positronium Hyperfine Splitting" (A. Ishida, 17th ICEPP Symposium, 21 Feb 2011, Nagano, Japan) Japanese(pdf)
"Precise Measurement of Positronium Hyperfine Splitting" (A. Ishida, GCOE「未来を拓く物理科学結集教育研究拠点」第5回RAキャンプ, 18 Feb 2011, Izunokuni, Shizuoka, Japan) Japanese(pdf)
"Precise Measurement of Positronium Hyperfine Splitting using the Zeeman Effect" (A. Ishida, JPS 2010 autumn meeting, 14 Sep 2010, Kyushu Institute of Technology, Kitakyushu, Fukuoka, Japan) Japanese(pdf)
"Measurement of Hyperfine Splitting of Positronium (1. Indirect Measurement)" (A. Ishida, T2K Seminar, 14 Jul 2010, J-PARC, Ibaraki, Japan) English(pdf)
"Precise Measurement of Positronium Hyperfine Splitting (Interim Report)" (A. Ishida, The 47th Annual Meeting on Radioisotope and Radiation Research, 7--9 Jul 2010, National Museum of Emerging Science and Innovation, Tokyo, Japan) Japanese(pdf)
"Precise Measurement of Positronium Hyperfine Splitting using Zeeman Effect" (A. Ishida, 39th Polish Seminar on Positron Annihilation (PSPA10), 20--25 Jun 2010, Dom Pracy Tworczej SDP, Kazimierz Dolny, Poland) English(pdf)
"Precise Measurement of Positronium Hyperfine Splitting using Zeeman Effect" (A. Ishida, JPS 65th annual meeting, 23 Mar 2010, Okayama University, Okayama, Japan) Japanese(pdf)
"Precise Measurement of Positronium Hyperfine Splitting using Zeeman Effect" (A. Ishida, 16th ICEPP Symposium, 14--17 Feb 2010, Nagano, Japan) Japanese(pdf)
"Precise Measurement of HFS of Positronium using Zeeman Effect" (A.Ishida, Advanced Science Research Symposium 2009 (ASR 2009), 10--12 November 2009, Techno Community Square Ricotti, Tokai, Japan) English(pdf)
"Precise Measurement of Positronium Hyperfine Splitting -Interim Report-" (A. Ishida, KEK Cryogenics Science Center Sminar, 8 Oct 2009, KEK, Ibaraki, Japan) Japanese(pdf)
"Precise measurement of HFS of positronium II (Current status and prospects)" (A. Ishida, JPS 2009 autumn meeting, 13 Sep 2009, Konan University, Hyogo, Japan) Japanese(pdf)
"Precise measurement of HFS of positronium"(Poster) (A. Ishida, XV International workshop on low energy positron and positronium physics (POSMOL 2009), 29 July -- 1 August 2009, Toronto, Canada) English(pdf)
"Precise measurement of HFS of positronium"(Poster) (A. Ishida, XXVI International Conference on Photonic, Electronic, and Atomic Collisions (ICPEAC 2009), 22 -- 28 July 2009, Kalamazoo, Michigan, the USA) Poster(English)(pdf), Abstract(English) A. Ishida et al., J. Phys.: Conf. Ser. 194 152021
"Precise Measurement of the positronium HFS I (Outline)" (A. Ishida, JPS 64th annual meeting, 27 Mar 2009, Rikkyo University, Tokyo, Japan) Japanese(pdf)
"Precise Measurement of Positronium Hyperfine Splitting" (A. Ishida, 15th ICEPP Symposium, 22--25 Feb 2009, Nagano, Japan) Japanese(pdf)
"Precise Measurement of HFS of Positronium II Report on Test Experiment using Zeeman Effect" (A. Ishida, Kyoto University Research Reactor Institute Special Workshop "Positron Science and its Application to Science and Technology", 5 Dec 2008, Kyoto University Research Reactor Institute, Osaka, Japan) Japanese(pdf)
"Precise measurement of hyperfine splitting of Positronium (III) (gamma-ray detectors)" (A. Ishida, JPS 2008 autumn meeting, 21 Sep 2008, Yamagata University, Yamagata, Japan) Japanese(pdf) English(pdf, translated from Japanese version)
"Precise measurement of positronium hyperfine structure II (Design of the gamma ray detector)," (A. Ishida, JPS 63rd annual meeting, 25 Mar 2008, Kinki University, Osaka, Japan) Japanese(pdf)