structure of exotic hadrons by radiative decay

• Project/Area Number: 16K05384
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: IMAI KENICHI 国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門 原子力科学研究所 先端基礎研究センター, 客員研究員 (70025493)
• Co-Investigator(Kenkyū-buntansha): 長谷川 勝一 国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門 原子力科学研究所 先端基礎研究センター, 研究主幹 (90391333)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2017: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000); Fiscal Year 2016: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• Keywords: エキゾチック八ドロン / 電磁崩壊 / ガンマ線検出器 / ハイペロン / エキゾチックハドロン / ハドロン / ストレンジネス / 電磁放射

Outline of Final Research Achievements

Ordinary baryons consist of three quarks. Some hyperon resonannces can not be explained bythis three quark picture and are called exotic hadrons. The structure of exotic hadron is not known and hot topics in hadron physics. We proposed to study their structure by their radiative decay, and carryied out the simulation study of its measurement. According to the simulation, we have designed a gamma ray position detector and developed the detector and studied its performance. We have found we can measure the radiative decay together with the exisiting hyperon spectrometer.

Academic Significance and Societal Importance of the Research Achievements

エキゾチックハドロンはハドロン物理学の大きな研究テーマである。その存在はほぼ確かだが、その存在の根拠となる理論は明確でなく、さらにはその構造についても実験的な知見はまだほとんどない。原子核やハドロンの構造の研究についてはγ線分光が極めて有効であったことがよく知られている。本研究はエキゾチックハドロンの有力候補であるハイペロン共鳴について初めてγ線崩壊を測定することを提案し、その実現可能性をシミレーションによりあきらかにした。さらにそのためのγ線位置検出器の開発研究を行い、実際に実験可能なことを明らかにした。

Research Products

• [Journal Article] Observation of a Be double hypernucleus in the J-PARC E07 experiment (2019)
  • Author(s): H.Ekawa, S.Hasegawa, K.Imai et al.,
  • Journal Title: Progress of Theoretical and Experimental Physics. Volume: 2019-2 Issue: 2
  • DOI: 10.1093/ptep/pty149
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The First Determination of the Level Structure ofan sd-shell Hypernucleus 19F(Lambda) (2018)
  • Author(s): S.B.Yang, S.Hasegawa, K.Imai et al.,
  • Journal Title: Phys. Rev. Lett. Volume: 120 Issue: 13 Pages: 132505-132505
  • DOI: 10.1103/physrevlett.120.132505
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Measurement of Radiative Decay of Lambda(1405) by using Hyperon Spectrometer at J-PARC (2017)
  • Author(s): S,H,Hwang, K.Imai
  • Journal Title: JPS Conf. Proc. Volume: 17
  • DOI: 10.7566/jpscp.17.033010
  • Peer Reviewed
• [Journal Article] Interference effect between φ and Λ(1520) production channels in the γp → K+K－p reaction near threshold (2016)
  • Author(s): S. Y. Ryu, J. K. Ahn, T. Nakano, J. Y. Chen, S. Date, H. Ejiri, M. Fujiwara, T. Hotta, S. H. Hwang, K. Imai, T. Ishikawa, T. Iwata, H. Kohri, Y. Kon, N. Kumagai, Y. Maeda, S. Makino, T. Matsuda, N. Matsuoka, T. Mibe, M. Miyabe, M. Miyachi, Y. Morino, N. Muramatsu, R. Murayama, Y. Ohashi, H. Ohkuma, et al.
  • Journal Title: Physical Review Letter Volume: 116 Issue: 23 Pages: 232001-232006
  • DOI: 10.1103/physrevlett.116.232001
  • Peer Reviewed / Int'l Joint Research
• [Presentation] Possible extension of J-PARC E42/45 experiment and upgrade of HypTPC spectrometer (2019)
  • Author(s): Kenichi IMAI
  • Organizer: Korea-Japan joint workshop on J-PARC hadron physics
  • Int'l Joint Research / Invited
• [Presentation] Summary (2016)
  • Author(s): Kenichi Imai
  • Organizer: 14th Int. Conf. on Meson-Nucleon Physics and structure of Nucleon
  • Place of Presentation: Kyoto, Japan
  • Year and Date: 2016-07-25
  • Int'l Joint Research / Invited