study of the quark counting rule in the transition region from non-perturbative QCD to perturbative QCD

• Project/Area Number: 18K03674
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 15020:Experimental studies related to particle-, nuclear-, cosmic ray and astro-physics
• Research Institution: Gifu University
• Principal Investigator: Sumihama Mizuki 岐阜大学, 教育学部, 准教授 (10396426)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2020: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2018: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
• Keywords: クォークカウンティング則 / ハドロン構造 / ハドロン光生成反応 / 光センサー / シンチレーション検出器 / エキゾチックバリオン / ハドロン / クォーク描像

Outline of Final Research Achievements

To study the quark counting rule, the experiment of the meson photoproduction carried out at Spring-8/LEPS1 and LEPS2 in the energy range where the transfer region from the non-perturbative QCD to the perturbative QCD. The data taken is enough quality and statistics for this study. The energy dependences of meson photoproductions have been calculated. For this experiment, the beam profile of the circular polarized photon beam was measured. To monitor the profile of the linearly polarized photon beam, the monitor with the MPPC array was developed. It is well performed. The start counter with MPPCs was developed to achieve the 130 ps time resolution. The calorimeter to detect neutral particles was modified and studied for its performance. The energy calibration was done by the minimum ionization peak of cosmic rays.

Academic Significance and Societal Importance of the Research Achievements

これまでのハドロン実験は、生成・崩壊過程の観測量から粒子の量子数の決定を行ってきたが、エキゾチックハドロンの構造解明に至っていない。本研究はクォークカウンティング則からクォーク数を決定するという新たな手法で、そのための、検証になる。本研究ではハドロン光生成反応実験を行った。そのスケーリングの挙動が分かれば、さらにエキゾチックハドロンを呼ばれるハドロンの内部構造の研究が進むことは間違いない。本研究を通して、MPPCを用いた検出器開発も行った。磁場に強く、高レート下でも動作し、非常にコンパクトで感度の良いMPPCの性能を利用して、ビームモニターや時間測定カウンターの開発が進み、汎用性を示せた。

Research Products

• [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] Measurement of neutral pion photoproduction off the proton with the large acceptance electromagnetic calorimeter BGOegg (2019)
  • Author(s): Muramatsu N .and LEPS2/BGOegg Collaboration
  • Journal Title: Physical Review C Volume: 100 Issue: 5 Pages: 055202-055202
  • DOI: 10.1103/physrevc.100.055202
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] First Measurements of Absolute Branching Fractions of the Ξc0 Baryon at Belle (2019)
  • Author(s): Li Y.B.、and Belle Collaboration
  • Journal Title: Physical Review Letters Volume: 122 Issue: 8 Pages: 082001-082001
  • DOI: 10.1103/physrevlett.122.082001
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Observation of Ξ(1620)0 and Evidence for Ξ(1690)0 in Ξc+→Ξ?π+π+ Decays (2019)
  • Author(s): Sumihama M.、and Belle Collaboration
  • Journal Title: Physical Review Letters Volume: 122 Issue: 7 Pages: 072501-072501
  • DOI: 10.1103/physrevlett.122.072501
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Measurements of branching fraction and direct CP asymmetry in B±→KS0KS0K± and a search for B±→KS0KS0π± (2019)
  • Author(s): Kaliyar A.?B.、and Belle Collaboration
  • Journal Title: Physical Review D Volume: 99 Issue: 3 Pages: 031102-031102
  • DOI: 10.1103/physrevd.99.031102
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Production cross sections of hyperons and charmed baryons from e+e? annihilation near s=10.52??GeV (2018)
  • Author(s): Niiyama M.、Sumihama M.、Nakano T. and Belle Collaboration
  • Journal Title: Physical Review D Volume: 97 Issue: 7 Pages: 072005-072005
  • DOI: 10.1103/physrevd.97.072005
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Observation of an Excited Ω? Baryon (2018)
  • Author(s): Yelton J.、and Belle Collaboration
  • Journal Title: Physical Review Letters Volume: 121 Issue: 5 Pages: 052003-052003
  • DOI: 10.1103/physrevlett.121.052003
  • Peer Reviewed / Int'l Joint Research
• [Presentation] SPring-8/LEPS2実験に用いるサンプリングカロリメータの磁場による影響の評価 (2021)
  • Author(s): 水田亮, 住浜水季, 柴田泰地, 板津克昌, 楳田紗里, 中村和希, 時安敦史, 吉田千尋, 與曽井優, 小早川亮, 渡邊憲
  • Organizer: 第76回日本物理学会年次大会
• [Presentation] SPring-8/LEPS2ソレノイドスペクトロメータ用トリガー検出器の開発とその性能評価Ⅲ (2020)
  • Author(s): 水田亮, 與曽井優, 住浜水季,E.A. Strokovsky, 山本林那, 渡邊憲
  • Organizer: 第75回日本物理学会年次大会
• [Presentation] SPring-8/LEPS実験における円偏光ビーム生成と偏極HD標的開発 (2020)
  • Author(s): 柳井優花, 與曽井優, 郡英輝, 堀田智明, 桂川仁志, 村松憲仁, 住浜水季, 成田龍哉, 太田岳史
  • Organizer: 第75回日本物理学会年次大会
• [Presentation] SPring-8/LEPS2ソレノイドスペクトロメータ用トリガー検出器の開発とその性能評価Ⅲ (2020)
  • Author(s): 水田亮, 與曽井優, 住浜水季, E.A. Strokovsky , 山本林那, 渡邊憲
  • Organizer: 日本物理学学会
• [Presentation] Studies of Xi(1620)^0 and Xi(1690)^0 hyperons at Belle (2019)
  • Author(s): Mizuki Sumihama, and Belle collaboration
  • Organizer: The 15th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon (MENU 2019)
  • Int'l Joint Research
• [Presentation] Recent results on hyperons and charmed baryons at Belle (2019)
  • Author(s): Mizuki Sumihama, and Belle collaboration
  • Organizer: The 15th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon (MENU 2019)
  • Int'l Joint Research