Photoproduction of exotic six-quark dibaryon states

• Project/Area Number: 19H01902
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 15020:Experimental studies related to particle-, nuclear-, cosmic ray and astro-physics
• Research Institution: Tohoku University
• Principal Investigator: Ishikawa Takatsugu 東北大学, 電子光理学研究センター, 助教 (40400220)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥17,160,000 (Direct Cost: ¥13,200,000、Indirect Cost: ¥3,960,000); Fiscal Year 2021: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2020: ¥11,310,000 (Direct Cost: ¥8,700,000、Indirect Cost: ¥2,610,000); Fiscal Year 2019: ¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000)
• Keywords: ダイバリオン / コヒーレント光生成反応 / ハドロン分光 / ハドロン間相互作用

Outline of Research at the Start

6 つのクォークからなるエキゾティックな粒子「ダイバリオン」の性質を、重陽子標的に対して2つの中性メソンと重陽子を終状態とする光生成反応で詳細に調べる。ダイバリオンの性質を詳細に調べ、存在するダイバリオンの系統性から、強い力で相互作用するクォーク・グルーオンの複合粒子「ハドロン」がどのように構成されるかを解明することを目指す。

Outline of Final Research Achievements

Hadrons are composite particles of several quarks, and they are classified into two: three quark baryons and quark-antiquark mesons. The structure and interaction of hadrons provides crucial insight into the non-perturbative mechanisms in quantum chromodynamics. We have experimentally studied coherent photoproduction of double neutral mesons on the deuteron at incident photon energies below 1.2 GeV. We have measured the total and differential cross sections for two neutral-pion production and neutral-pion and eta meson production, observing several two-baryon resonance (dibaryon) states. We have succeeded to observe several dibaryon states or excited states of the deuteron, belonging to a new type of hadrons.

Academic Significance and Societal Importance of the Research Achievements

本研究では、コヒーレントダブルメソン光生成反応でダイバリオンという６つのクォークから構成されるハドロンの観測に成功した。新たなハドロンの形態であるダイバリオンを観測したことで、クォークが単独では取り出せないという閉じ込め問題に新たな知見を与える。我々が発見したダイバリオンの一部がドイツ・ボン大学の ELSA 施設で追認されたり、反応計算を行う理論研究者も現れ始めたり、ダイバリオンの分光という新たな分野を切り拓いた。またダイバリオンの構造に対する理解は、未だよく理解されていない核物質の状態方程式や中性子星の内部構造に対して極めて重要な情報をもたらす。

Research Products

• [Journal Article] Coherent photoproduction of the neutral-pion and η-meson on the deuteron at incident energies below 1.15 GeV (2022)
  • Author(s): T. Ishikawa, A. Fix et al.
  • Journal Title: Physical Review C Volume: 105 Issue: 4
  • DOI: 10.1103/physrevc.105.045201
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] SPring-8 LEPS2 beamline: A facility to produce a multi-GeV photon beam via laser Compton scattering (2022)
  • Author(s): N. Muramatsu, T. Ishikawa et al.
  • Journal Title: arXiv:2112.07832 Volume: 2112
  • Open Access / Int'l Joint Research
• [Journal Article] K－d→πΛN reaction for studying charge symmetry breaking in the ΛN interaction (2022)
  • Author(s): Yutaro Iizawa, Daisuke Jido, Takatsugu Ishikawa
  • Journal Title: arXiv:2201.06737 Volume: 2201
  • Open Access
• [Journal Article] Resonance-like structure near the ηd threshold in the γd→ηd reaction (2021)
  • Author(s): T. Ishikawa et al.
  • Journal Title: Physical Review C Volume: 104 Issue: 5 Pages: 1-6
  • DOI: 10.1103/physrevc.104.l052201
  • Peer Reviewed / Open Access
• [Journal Article] Continuous timing measurement using a data-streaming DAQ system (2021)
  • Author(s): Honda Ryotaro、Aramaki Takashi、Asano Hidemitsu、Akaishi Takaya、Chang W C、Igarashi Youichi、Ishikawa Takatsugu、Kajikawa Shunsuke、Ma Yue、Nagai Kei、Noumi Hiroyuki、Sako Hiroyuki、Shirotori Kotaro、Takahashi Tomonori
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 2021 Issue: 12 Pages: 1-20
  • DOI: 10.1093/ptep/ptab128
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Coherent Neutral Pion and eta Meson Photoproduction on the Deuteron (2021)
  • Author(s): Ishikawa Takatsugu、for the FOREST collaboration
  • Journal Title: Few-Body Systems Volume: 62 Issue: 3
  • DOI: 10.1007/s00601-021-01621-4
  • Peer Reviewed
• [Journal Article] Extension of the J-PARC Hadron Experimental Facility: Third White Paper (2021)
  • Author(s): Kazuya Aoki, Takatsugu Ishikawa et al. (Taskforce on the extension of the Hadron Experimental Facility)
  • Journal Title: arXiv: 2110.04462 Volume: 2110
  • Open Access
• [Journal Article] Search for NΔ Resonance State Via the Exclusive Measurement of γd → d π+π- Reaction (2021)
  • Author(s): Toyama Y.、Ishikawa T.、Kanda H.、Kaneta M.、Maeda K.、Muroi Y.、Nagao S.、Nakamura S. N.、For the NKS2 Collaboration
  • Journal Title: Few-Body Systems Volume: 63 Issue: 1 Pages: 15-15
  • DOI: 10.1007/s00601-021-01719-9
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Study of high-rate capabilities of CITIROC1A and PETIROC2A ASICs (2021)
  • Author(s): R. Honda, T. Ishikawa, S. Kajikawa, Y. Kimura, H. Noumi, K. Shirotori, R. Tatsumi, and N. Tomida
  • Journal Title: ELPH Annual Report 2020, Tohoku University Volume: 2020 Pages: 13-23
• [Journal Article] Current status of the FOREST/BLC experiments at ELPH (2021)
  • Author(s): T. Ishikawa, K. Aoki, H. Fujioka, Y. Honda, T. Hotta, K. Itahashi, H. Kanda, H. Kawai, K. Maeda, Y. Matsumura, M. Miyabe, S. Miyata, N. Muramatsu, H. Ohnishi, K. Ozawa, Y. Sada, H. Shimizu, M. Tabata, A.O. Tokiyasu, and Y. Tsuchikawa
  • Journal Title: ELPH Annual Report 2020, Tohoku University Volume: 2020 Pages: 71-75
• [Journal Article] Testing a prototype plastic scintillator hodoscope for the J-PARC E50 experiment (2021)
  • Author(s): T. Ishikawa, M. Miyabe, H. Noumi2;, H. Ohnishi, Y. Sada, K. Shirotori, A.O. Tokiyasu, and C. Yoshida
  • Journal Title: ELPH Annual Report 2020, Tohoku University Volume: 2020 Pages: 77-80
• [Journal Article] Coherent photoproduction of the neutral pion and eta meson on the deuteron (II) (2021)
  • Author(s): T. Ishikawa et al.
  • Journal Title: ELPH Annual Report 2020, Tohoku University Volume: 2020 Pages: 81-84
• [Journal Article] Experimental study of (p, 2p) reactions at 392 MeV on 12C, 16O, 40Ca and 208Pb nuclei leading to low-lying states of residual nuclei (2020)
  • Author(s): Tetsuo Noro, Takatsugu Ishikawa et al.
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 2020 Issue: 9
  • DOI: 10.1093/ptep/ptaa109
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Differential cross sections, photon beam asymmetries, and spin density matrix elements of ω photoproduction off the proton at Eγ=1.3?2.4 GeV (2020)
  • Author(s): Muramatsu N. et al. LEPS2/BGOegg Collaboration
  • Journal Title: Physical Review C Volume: 102 Issue: 2 Pages: 025201-025201
  • DOI: 10.1103/physrevc.102.025201
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Search for η′ Bound Nuclei in the C12(γ,p) Reaction with Simultaneous Detection of Decay Products (2020)
  • Author(s): N.Tomida, N.Muramatsu, M.Niiyama, J.K.Ahn, W.C.Chang, J.Y.Chen, M.L.Chu, S.Date, T.Gogami, H.Goto, H.Hamano, T.Hashimoto, Q.H.He, K.Hicks, T.Hiraiwa, Y.Honda, T.Hotta, H.Ikuno, Y.Inoue, T.Ishikawa, I.Jaegle, J.M.Jo, Y.Kasamatsu, H.Katsuragawa, S.Kido, Y.Kon, T.Maruyama, (全63名）
  • Journal Title: Physical Review Letters Volume: 124 Issue: 20 Pages: 202501-202501
  • DOI: 10.1103/physrevlett.124.202501
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] ωN scattering length from ω photoproduction on the proton near the reaction threshold (2020)
  • Author(s): Ishikawa T.、7番目
  • Journal Title: Physical Review C Volume: 101 Issue: 5 Pages: 052201-052201
  • DOI: 10.1103/physrevc.101.052201
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Non-strange dibaryons studied in coherent double neutral-meson photoproduction on the deuteron (2020)
  • Author(s): Takatsugu Ishikawa et al.
  • Journal Title: EPJ Web of Conferences Volume: 241 Pages: 01007-01007
  • DOI: 10.1051/epjconf/202024101007
  • Peer Reviewed / Open Access
• [Journal Article] ωN scattering length from ω photoproduction on the proton near the threshold (2020)
  • Author(s): Takatsugu Ishikawa et al.
  • Journal Title: AIP Conference Proceedings Volume: 2249 Pages: 030027-030027
  • DOI: 10.1063/5.0008651
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] ωN scattering length from ω photoproduction on the proton near the threshold (2020)
  • Author(s): T. Ishikawa et al.
  • Journal Title: AIP Conference Proceedings Volume: 2319 Pages: 080017-080017
  • DOI: 10.1063/5.0036979
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Neutron-neutron scattering length from π+ photoproduction on the deuteron (2020)
  • Author(s): S.X. Nakamura, T. Ishikawa, T. Sato
  • Journal Title: arXiv preprint Volume: nucl-th
  • Open Access / Int'l Joint Research
• [Journal Article] ηN Scattering Parameters and Possible η'd Bound State from η Photoproduction on the Deuteron (2020)
  • Author(s): T. Ishikawa et al.
  • Journal Title: Acta Physica Polonica B Volume: 51 Issue: 1 Pages: 27-32
  • DOI: 10.5506/aphyspolb.51.27
  • Peer Reviewed / Open Access
• [Journal Article] Non-strange dibaryons studied in coherent double neutral-meson photoproduction on the deuteron (2020)
  • Author(s): T. Ishikawa et al.
  • Journal Title: Acta Physica Polonica B Volume: 51 Issue: 1 Pages: 329-332
  • DOI: 10.5506/aphyspolb.51.329
  • Peer Reviewed / Open Access
• [Journal Article] Performance of the FOREST/BLC Spectrometer for Study of the η-nucleon Interaction via the γd→pηn Reaction (2020)
  • Author(s): S. Miyata, T. Ishikawa et al.
  • Journal Title: Springer Proceedings in Physics Volume: 238 Pages: 705-708
  • DOI: 10.1007/978-3-030-32357-8_113
  • ISBN: 9783030323561, 9783030323578
  • Peer Reviewed
• [Journal Article] Study of Non-strange Dibaryon Resonances Via Coherent Double Neutral-Meson Photoproduction from the Deuteron (2020)
  • Author(s): T. Ishikawa et al.
  • Journal Title: Springer Proceedings in Physics Volume: 238 Pages: 609-613
  • DOI: 10.1007/978-3-030-32357-8_96
  • ISBN: 9783030323561, 9783030323578
  • Peer Reviewed
• [Journal Article] 最近の研究から「光子ビームで探るクォーク・グルーオン多体系―ダイバリオンの発見から分光へ」 (2020)
  • Author(s): 石川貴嗣、笠木治郎太
  • Journal Title: 日本物理学会誌 BUTSURI Volume: 75
  • Peer Reviewed
• [Journal Article] Measuring Space-Time Properties of the Δ(1232) via Bose-Einstein Correlations (2019)
  • Author(s): Qinghua He, Takatsugu Ishikawa et al.
  • Journal Title: JPS Conference Proceedings Volume: 26
  • DOI: 10.7566/jpscp.26.024004
  • Peer Reviewed / Open Access
• [Journal Article] Non-strange Dibaryon Resonances Observed in Coherent Double Neutral-Pion Photoproduction on the Deuteron (2019)
  • Author(s): Takatsugu Ishikawa et al.
  • Journal Title: JPS Conference Proceedings Volume: 26
  • DOI: 10.7566/jpscp.26.022014
  • Peer Reviewed / Open Access
• [Journal Article] Experimental Study of Di-quark Correlation by CharmedBaryon Spectroscopy at J-PARC High-Momentum Secondary Beam Line (2019)
  • Author(s): Y. Komatsu
  • Journal Title: JPS Conf. Proc. Volume: - Pages: 022029-022029
  • DOI: 10.7566/jpscp.26.022029
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] eta photoproduction off the deuteron and low-energy eta-nucleon interaction (2019)
  • Author(s): S.X. Nakamura, H. Kamano, T. Ishikawa
  • Journal Title: JPS Conference Proceedings Volume: 26 Pages: 0230011-4
  • DOI: 10.7566/jpscp.26.023001
  • Peer Reviewed / Open Access
• [Presentation] Non-strange dibaryon resonances explored at J-PARC (2022)
  • Author(s): Takatsugu Ishikawa
  • Organizer: Second International Workshop on the Extension Project for the J-PARC Hadron Experimental Facility (2nd J-PARC HEF-ex WS)
  • Int'l Joint Research
• [Presentation] π-ビームを使った陽子標的でのηメソン生成 (2022)
  • Author(s): 石川貴嗣
  • Organizer: J-PARCハドロン研究会2022
• [Presentation] 閾値近傍における重水素標的でのコヒーレントπ^0 η光生成反応 (II) (2022)
  • Author(s): 石川貴嗣
  • Organizer: 日本物理学会第77回年次大会
• [Presentation] Coherent neutral pion and eta meson photoproduction on the deuteron (2021)
  • Author(s): Takatsugu Ishikawa
  • Organizer: The 19th International Conference on Hadron Spectroscopy and Structure in memoriam Simon Eidelman (HADRON 2021)
  • Int'l Joint Research
• [Presentation] Coherent neutral pion and eta meson photoproduction on the deuteron (2021)
  • Author(s): Takatsugu Ishikawa
  • Organizer: the 24th International Spin Symposium (SPIN2021)
  • Int'l Joint Research
• [Presentation] ηメソンと重陽子の結合状態の観測 (2021)
  • Author(s): 石川貴嗣
  • Organizer: 第7回クラスター階層領域研究会
• [Presentation] γd→π0 π0 π0 d反応に見られるd* (2380)ダイバリオンのシグナル (2021)
  • Author(s): 石川貴嗣
  • Organizer: ELPH workshop C031 (多彩なビーム実験と多様な理論的手法で迫るハドロン間相互作用)
• [Presentation] ハドロン実験用電磁カロリメータの開発 (2021)
  • Author(s): 石川貴嗣
  • Organizer: 測定器開発プラットフォーム& テストビームライン研究会
• [Presentation] J-PARC E50 実験前方ホドスコープ用プラスチックシンチレータの時間分解能 (2021)
  • Author(s): 石川貴嗣
  • Organizer: 日本物理学会2021 年秋季大会, オンライン
• [Presentation] γd→π0 π0 π0 d反応に見られるd* (2380)ダイバリオンのシグナル (2021)
  • Author(s): 石川貴嗣
  • Organizer: 日本物理学会2021 年秋季大会, オンライン
• [Presentation] Coherent neutral pion and eta meson photoproduction on the deuteron (2021)
  • Author(s): Takatsugu Ishikawa
  • Organizer: Yamada Conference LXXII: The 8th Asia-Pacific conference on Few-Body problems in Physics (APFB2020)
  • Int'l Joint Research
• [Presentation] ηd threshold structure from the γd→π0ηd reaction (2021)
  • Author(s): Takatsugu Ishikawa
  • Organizer: Hadron in Nucleus 2020 (HIN20)
  • Int'l Joint Research
• [Presentation] Hadron physics from meson photoproduction experiments at ELPH (2021)
  • Author(s): Takatsugu Ishikawa
  • Organizer: 東京工業大学量子物理学ナノサイエンス第307 回セミナー
  • Invited
• [Presentation] nn scattering length from positive pion photoproduction on the deuteron (2021)
  • Author(s): Takatsugu Ishikawa
  • Organizer: 東京工業大学インフォーマルセミナー
  • Invited
• [Presentation] Low-energy neutron-neutron scattering studied with pion photoproduction on the deuteron (2021)
  • Author(s): Satoshi X Nakamura
  • Organizer: Hadron in Nucleus 2020 (HIN20)
  • Int'l Joint Research
• [Presentation] Hadron-hadron scattering length from meson photoproduction (2020)
  • Author(s): Takatsugu Ishikawa
  • Organizer: Joint THEIA-STRONG2020 and JAEA/Mainz REIMEI Web-Seminar
  • Int'l Joint Research / Invited
• [Presentation] Hadron-hadron scattering length from meson photoproduction (2020)
  • Author(s): 石川貴嗣
  • Organizer: ELPH workshop C029 “様々なフレーバー領域で探るクォーク・ハドロン多体系の分光と構造”
• [Presentation] 重水素標的におけるコヒーレントπ0η光生成反応によるηN散乱長の決定 (2020)
  • Author(s): 石川貴嗣
  • Organizer: 新学術領域研究「量子クラスターで読み解く物質の階層構造」 ワークショップ（第5回クラスター階層領域研究会）
• [Presentation] 仮想光子を使った nn 散乱長の精密測定による荷電対称性の破れの研究 (2020)
  • Author(s): 石川貴嗣
  • Organizer: 新学術領域研究「宇宙観測検出器と量子ビームの出会い。新たな応用への架け橋。」 ワークショップ（第2回領域全体会議）
• [Presentation] Determination of eta-nucleon scattering length from eta photoproduction on the deuteron (2020)
  • Author(s): 石川貴嗣
  • Organizer: 新学術領域研究「量子クラスターで読み解く物質の階層構造」 ワークショップ（第3回クラスター階層領域研究会）
• [Presentation] Neutron-neutron scattering length from π+ photoproduction on the deuteron (2020)
  • Author(s): 中村聡
  • Organizer: ELPH workshop C029 “様々なフレーバー領域で探るクォーク・ハドロン多体系の分光と構造”
  • Invited
• [Presentation] Photo-production of the eta-meson on the deuteron (2020)
  • Author(s): Takatsugu Ishikawa
  • Organizer: International Symposium on Clustering as a Window on the Hierarchical Structure of Quantum Systems (CLUSHIQ2020)
  • Int'l Joint Research
• [Presentation] Dibaryon photoproduction on the deuteron detecting two neutral pions and deuteron (2020)
  • Author(s): Takatsugu Ishikawa
  • Organizer: KEK/Tokai Internal workshop on “Physics of heavy-quark and exotic hadrons”
  • Int'l Joint Research / Invited
• [Presentation] Experimental study of a light exotic baryon with neutral meson photoproduction (2020)
  • Author(s): Yusuke Tsuchikawa
  • Organizer: KEK/Tokai Internal workshop on “Physics of heavy-quark and exotic hadrons”
  • Int'l Joint Research / Invited
• [Presentation] ωN scattering length from ω photoproduction on the proton near the threshold (2019)
  • Author(s): Takatsugu Ishikawa
  • Organizer: The 15th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon, MENU2019
  • Int'l Joint Research
• [Presentation] Non-Strange Dibaryons studied in coherent double neutral-meson photoproduction on the deuteron (2019)
  • Author(s): Takatsugu Ishikawa
  • Organizer: The 12th Internal workshop on the Physics of Excited Nucleons (NSTAR2019)
  • Int'l Joint Research
• [Presentation] ηN scattering parameters and possible η'N bound state from η photoproduction on the deuteron (2019)
  • Author(s): Takatsugu Ishikawa
  • Organizer: 3rd Jagiellonian Symposium on Fundamental and Applied Subatomic Physics
  • Int'l Joint Research / Invited
• [Presentation] Non-strange dibaryons studied in coherent double neutral-meson photoproduction on the deuteron (2019)
  • Author(s): Takatsugu Ishikawa
  • Organizer: 3rd Jagiellonian Symposium on Fundamental and Applied Subatomic Physics
  • Int'l Joint Research
• [Presentation] ωN scattering length from ω photoproduction on the proton near the threshold (2019)
  • Author(s): Takatsugu Ishikawa
  • Organizer: The 14th Asia-Pacific Physics Conference 2019 (APPC2019)
  • Int'l Joint Research
• [Presentation] Study of charge symmetry breaking from the precise and accurate measurement of the nn scattering length using virtual photons (2019)
  • Author(s): 石川 貴嗣
  • Organizer: 新学術領域研究「宇宙観測検出器と量子ビームの出会い。新たな応用への架け橋。」 ワークショップ（第1回領域全体会議）
• [Presentation] コヒーレントなダブルメソン光生成反応で探るダイバリオン共鳴, (2019)
  • Author(s): 石川 貴嗣
  • Organizer: ELPH workshop C024 “ハドロン構造における多粒子相関”
• [Presentation] Dynamical coupled-channels approach to electroweak reactions on nucleon and deuteron (2019)
  • Author(s): 中村 聡
  • Organizer: ELPH workshop C024 “ハドロン構造における多粒子相関”
  • Invited
• [Presentation] Dynamical coupled-channels approach to electroweak reactions on nucleon and deuteron (2019)
  • Author(s): Satoshi X Nakamura
  • Organizer: The 15th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon, MENU2019
  • Int'l Joint Research / Invited
• [Remarks] ηメソンと重陽子の結合状態の観測に成功
  • URL: https://www.tohoku.ac.jp/japanese/2021/11/press20211130-03-meson.html
• [Remarks] 光子ビームによるダイバリオン状態の研究
  • URL: http://apollo.lns.tohoku.ac.jp/hadron/mbr/ishikawa/j2021c.html
• [Remarks] 光子ビームによるダイバリオン状態の研究
  • URL: http://www.lns.tohoku.ac.jp/hadron/mbr/ishikawa/j2020c.html
• [Remarks] 光子ビームによるダイバリオン状態の研究
  • URL: http://www.lns.tohoku.ac.jp/hadron/mbr/ishikawa/j2019c.html
• [Funded Workshop] YITP internal workshop, Hadron in Nucleus 2020 (HIN20) (2021)