Development of software trigger for higher intensity rare muon decay experiment

• Project/Area Number: 17K14267
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: The University of Tokyo
• Principal Investigator: Uchiyama Yusuke 東京大学, 素粒子物理国際研究センター, 特任助教 (90580241)
• Research Collaborator: USAMI Masashi
• Project Period (FY): 2017-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2018: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2017: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
• Keywords: データ収集システム / トリガー / ミュー粒子稀崩壊探索 / 大強度加速器実験 / 計算機クラスター / 素粒子実験 / ミュー粒子稀崩壊 / レプトンフレーバーの破れ

Outline of Final Research Achievements

We worked on an outstanding issue in the MEG II experiment from both hardware and software points of view. The MEG II experiment will search for the lepton-flavor-violating rare muon decay, mu to e gamma decay, using the world's most intense muon beam. In the experiment, the treatment of the huge amount of data is one of the challenging points. In this study, we built a system to reduce the data size from 240 MB/s to 30 MB/s without loosing the signal efficiency, leading to more robust achievement of the target sensitivity.

Academic Significance and Societal Importance of the Research Achievements

分岐比10の-13乗以下のレプトンフレーバーを破るミュー粒子稀崩壊探索は素粒子のフレーバー研究の最重要課題の一つである。実験開始に先立ってデータの取り扱いを確立したことで，目標とする実験感度の達成をより確実のものとした本研究は，国際共同実験MEG IIの成功，ひいては物理学の進展に大きく寄与したといえる。本研究によりMEG II実験に必要なストレージコストを１～２千万円程度削減できた。増大するデータ量の取り扱いは分野全体の課題であり，本研究で確立したシステムと，開発した高計数率下の事象再構成法はMEG IIのみならず他の中小規模強度フロンティア素粒子実験に生かすことができる。

Research Products

• [Int'l Joint Research] Paul Scherrer Institute(スイス)
• [Int'l Joint Research] Budker Institute of Nuclear Physics/Joint Institute for Nuclear Research(ロシア連邦)
• [Int'l Joint Research] INFN Pisa/INFN Rome(イタリア)
• [Int'l Joint Research] Paul Scherrer Institute(スイス)
• [Int'l Joint Research] Budker Institute of Nuclear Physics(ロシア連邦)
• [Int'l Joint Research] INFN Pisa/INFN Roma(イタリア)
• [Journal Article] Hunting the muon's forbidden decay (2019)
  • Author(s): Angela Papa、Francesco Renga、Yusuke Uchiyama
  • Journal Title: CERN Courier Volume: May/June
  • Open Access / Int'l Joint Research
• [Journal Article] MEG II実験 ―分岐比10-14台でのμ+→e+γ崩壊探索― (2018)
  • Author(s): 家城佳、内山雄祐
  • Journal Title: 高エネルギーニュース Volume: 37 Pages: 1-10
  • Open Access
• [Journal Article] Design and test of the calibration system of the MEGII Pixelated timing Counter (2018)
  • Author(s): M. Rossella, et al.
  • Journal Title: Nuclear Instruments and Methods in Physics Research Section A Volume: - Pages: 300-302
  • DOI: 10.1016/j.nima.2018.10.129
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Development and commissioning of the 30 ps time resolution MEGII Pixelated Time detector (2018)
  • Author(s): P. W. Cattaneo, et al.
  • Journal Title: Nuclear Instruments and Methods in Physics Research Section A Volume: - Pages: 660-662
  • DOI: 10.1016/j.nima.2018.09.055
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] The design of the MEG II experiment (2018)
  • Author(s): A.M.Baldini, …, S.Ogawa et.al.
  • Journal Title: Eur. Phys. J. C Volume: 78 Issue: 5 Pages: 380-380
  • DOI: 10.1140/epjc/s10052-018-5845-6
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] MEG II offline computing (2019)
  • Author(s): Y. Uchiyama
  • Organizer: Global Developments of Researches in Lepton Flavor Physics with Muons
  • Int'l Joint Research
• [Presentation] MEG II offline computing (2019)
  • Author(s): Y. Uchiyama
  • Organizer: PSI User's Meeting BV50
  • Int'l Joint Research
• [Presentation] MEG II 実験における陽電子の時間再構成法の改善 (2019)
  • Author(s): 野内康介，他 MEG IIコラボレーション
  • Organizer: 日本物理学会第74回年次大会
• [Presentation] Full System of Positron Timing Counter Having Time Resolution under 40 psec with Fast Plastic Scintillator Readout by SiPMs (2019)
  • Author(s): M. Nishimura, P. W. Cattaneo, F. Berg, M. Biasotti, G.Boca, M. De Gerone, A. De Bari, M. Francesconi, L. Galli, F. Gatti, U. Hartmann, Z. Hodge, P.-R. Kettle, M. Nakao, D. Nicol, W. Ootani, A. Papa, S. Ritt, M. Rossella, E. Schmid, Y. Uchiyama, M. Usami, K. Yanai
  • Organizer: The 15th Vienna Conference on Instrumentation
  • Int'l Joint Research
• [Presentation] Large Scale Characterization of SiPMs in the MEG II Experiment (2018)
  • Author(s): Y. Uchiyama
  • Organizer: International Conference on the Advancement of Silicon Photomultipliers
  • Int'l Joint Research / Invited
• [Presentation] MEG II 実験陽電子スペクトロメータにおける検出効率改善のための再構成アルゴリズムの研究 (2018)
  • Author(s): 宇佐見正志，他 MEG IIコラボレーション
  • Organizer: 日本物理学会2018年秋季大会
• [Presentation] μ+ → e+γ 探索実験 MEG II 2018年度の展望 (2018)
  • Author(s): 内山雄祐，他 MEG IIコラボレーション
  • Organizer: 日本物理学会第73回年次大会
• [Presentation] MEG II Offline and Analysis Resources (2018)
  • Author(s): Y. Uchiyama
  • Organizer: PSI User's Meeting BV49
  • Int'l Joint Research
• [Presentation] Scintillation detectors in MEG (2017)
  • Author(s): Y. Uchiyama
  • Organizer: The Fall 2017 CALICE collaboration meeting
  • Int'l Joint Research / Invited
• [Remarks] MEG実験ホームページ
  • URL: http://meg.icepp.s.u-tokyo.ac.jp/