大型液体キセノン検出器XENONnTを用いた暗黒物質の直接探索

• Project/Area Number: 22KJ1516
• Project/Area Number (Other): 21J01817 (2021-2022)
• Research Category: Grant-in-Aid for JSPS Fellows
• Allocation Type: Multi-year Fund (2023); Single-year Grants (2021-2022)
• Section: 国内
• Review Section: Basic Section 15020:Experimental studies related to particle-, nuclear-, cosmic ray and astro-physics
• Research Institution: Nagoya University
• Principal Investigator: 小林 雅俊 名古屋大学, 素粒子宇宙起源研究所, 特任助教
• Project Period (FY): 2023-03-08 – 2024-03-31
• Project Status: Completed (Fiscal Year 2023)
• Budget Amount: ¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000); Fiscal Year 2023: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2022: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2021: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
• Keywords: 暗黒物質 / 液体キセノン / 光検出器 / ニュートリノ / トリチウム / キセノン / 低放射能技術

Outline of Research at the Start

本研究では大型液体キセノン検出器XENONnTを用い、我々の宇宙に存在する未知の質量である暗黒物質を発見することを目指す。XENONnT実験は2022年度に初期観測データを用いた解析結果を公表した後、更なるバックグラウンド低減を経て観測が継続されており、本データを解析して暗黒物質探索を行う。また更なる将来実験へ向けたR&Dにも取り組んでいく。

Outline of Annual Research Achievements

様々な天文観測から、我々の宇宙には暗黒物質と呼ばれる未知の物質が通常の物質の５倍以上存在すると言われている。その中でも有力な候補が未発見の素粒子で、質量が重く弱い相互作用程度のスケールで核子と相互作用するWIMPや、電子と弱く相互作用するアクシオン様粒子(ALP)などが挙げられてきた。
本研究では、イタリアで行われる国際実験XENONnT実験により、キセノンと暗黒物質のごく稀な相互作用を通して暗黒物質探索を行った。研究期間全体を通して主に、XENONnT実験の検出器に関するコミッショニング、物理データ取得およびその解析に取り組んだ。XENONnT実験は2021年度から初期観測を開始しており、報告者はイタリアに長期滞在、現地の運転責任者としてクリプトンや中性子を用いたキャリブレーションデータの取得や、検出器にかける電圧の最適化など、安定的なデータの取得のための取り組みを指揮した。また得られたデータの解析として、特に検出器中のキセノン純度の影響を明らかにし、2022年度には太陽アクシオンやALPなどに関して世界最高感度の探索結果を発表している。2023年度には、同データを用い最も重要なモデルであるWIMPに関しても前身実験の感度を約2倍更新する探索を行うとともに、太陽から飛来するニュートリノ事象の探索など暗黒物質にとどまらない物理・天文現象の観測にも取り組んだ。
また並行して、名古屋大学における小型装置を用いたXENONnT実験の将来計画に関するR&Dにも取り組んだ。キセノン純度のさらなる向上のため、ラドンやトリチウムといったキセノン中の放射性不純物を削減するとともに、微量な不純物を定量的に測定するための技術開発に取り組み、日本物理学会などで発表を行なっている。

Research Products

• [Int'l Joint Research] INFN LNGS/INFN Bologna/INFN Napoli(イタリア)
• [Int'l Joint Research] Columbia University/Chicago University/UC San Diego(米国)
• [Int'l Joint Research] MPIK/Frieburg University/University of Munster(ドイツ)
• [Int'l Joint Research] Tsinghua University/WestLake University/CUHK-Shenzhen(中国)
• [Int'l Joint Research] Subatech/LPNHE(フランス)
• [Int'l Joint Research]
• [Int'l Joint Research] INFN Laboratori Nazionali del Gran Sasso/L'Aquila University/INFN Bologna(イタリア)
• [Int'l Joint Research] Columbia University/Chicago University/UC San Diego(米国)
• [Int'l Joint Research] MPIK, Heidelberg/Freiburg University/University of Munster(ドイツ)
• [Int'l Joint Research] University of Zurich(スイス)
• [Int'l Joint Research] Tsinghua University(中国)
• [Int'l Joint Research]
• [Int'l Joint Research] INFN Laboratori Nazionali del Gran Sasso/L'Aquila University/INFN Bologna(イタリア)
• [Int'l Joint Research] Columbia University/Chicago University/UC San Diego(米国)
• [Int'l Joint Research] MPIK Heidelberg/Freiburg University/University of Munster(ドイツ)
• [Int'l Joint Research] University of Zurich(スイス)
• [Int'l Joint Research] Tsinghua University(中国)
• [Int'l Joint Research]
• [Journal Article] Design and performance of the field cage for the XENONnT experiment (2024)
  • Author(s): XENON collaboration, M. Kobayashi
  • Journal Title: The European Physical Journal C Volume: 84 Issue: 2 Pages: 1-12
  • DOI: 10.1140/epjc/s10052-023-12296-y
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Cosmogenic background simulations for neutrinoless double beta decay with the DARWIN observatory at various underground sites (2024)
  • Author(s): DARWIN Collaboration, M.Kobayashi
  • Journal Title: The European Physical Journal C Volume: 84 Issue: 1 Pages: 1-14
  • DOI: 10.1140/epjc/s10052-023-12298-w
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Search for events in XENON1T associated with gravitational waves (2023)
  • Author(s): XENON collaboration, M. Kobayashi
  • Journal Title: Physical Review D Volume: 108 Issue: 7
  • DOI: 10.1103/physrevd.108.072015
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Searching for Heavy Dark Matter near the Planck Mass with XENON1T (2023)
  • Author(s): XENON collaboration, M. Kobayashi
  • Journal Title: Physical Review Letters Volume: 130 Issue: 26 Pages: 1-8
  • DOI: 10.1103/physrevlett.130.261002
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] First Dark Matter Search with Nuclear Recoils from the XENONnT Experiment (2023)
  • Author(s): XENON collaboration, M. Kobayashi
  • Journal Title: Physical Review Letters Volume: 131 Issue: 4 Pages: 041003-19
  • DOI: 10.1103/physrevlett.131.041003
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The triggerless data acquisition system of the XENONnT experiment (2023)
  • Author(s): XENON collaboration, M. Kobayashi
  • Journal Title: Journal of Instrumentation Volume: 18 Issue: 07 Pages: 1-27
  • DOI: 10.1088/1748-0221/18/07/p07054
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Low-energy calibration of XENON1T with an internal 37Ar source (2023)
  • Author(s): XENON collaboration, Kobayashi M.
  • Journal Title: The European Physical Journal C Volume: 83 Issue: 6 Pages: 1-15
  • DOI: 10.1140/epjc/s10052-023-11512-z
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Detector signal characterization with a Bayesian network in XENONnT (2023)
  • Author(s): XENON collaboration, M. Kobayashi
  • Journal Title: Physical Review D Volume: 108 Issue: 1 Pages: 1-11
  • DOI: 10.1103/physrevd.108.012016
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A next-generation liquid xenon observatory for dark matter and neutrino physics (2023)
  • Author(s): J. Aalbers et al
  • Journal Title: Journal of Physics G Volume: 50, 013001 Issue: 1 Pages: 1-115
  • DOI: 10.1088/1361-6471/ac841a
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] An approximate likelihood for nuclear recoil searches with XENON1T data (2022)
  • Author(s): E. Aprile, K. Abe, F. Agostini, S. Ahmed Maouloud, M. Alfonsi, L. Althueser, B. Andrieu, E. Angelino, J. R. Angevaare, V. C. Antochi, D. Anton Martin, F. Arneodo, L. Baudis, A.L. Baxter, L. Bellagamba, R. Biondi, A. Bismark, S.Kazama et al.
  • Journal Title: Eur. Phys. J. C Volume: 82:989 Issue: 11 Pages: 1-10
  • DOI: 10.1140/epjc/s10052-022-10913-w
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Search for New Physics in Electronic Recoil Data from XENONnT (2022)
  • Author(s): E. Aprile, K. Abe, F. Agostini, S. Ahmed Maouloud, M. Alfonsi, L. Althueser, B. Andrieu, E. Angelino, J. R. Angevaare, V. C. Antochi, D. Anton Martin, F. Arneodo, L. Baudis, A.L. Baxter, L. Bellagamba, R. Biondi, A. Bismark, S.Kazama et al.
  • Journal Title: Phys. Rev. Lett. Volume: 129 161805 Issue: 16 Pages: 1-10
  • DOI: 10.1103/physrevlett.129.161805
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Double-weak decays of 124Xe and 136Xe in the XENON1T and XENONnT experiments (2022)
  • Author(s): E. Aprile, K. Abe, F. Agostini, S. Ahmed Maouloud, M. Alfonsi, L. Althueser, B. Andrieu, E. Angelino, J. R. Angevaare, V. C. Antochi, D. Anton Martin, F. Arneodo, L. Baudis, A.L. Baxter, L. Bellagamba, R. Biondi, A. Bismark, S.Kazama et al.
  • Journal Title: Phys. Rev. C Volume: 106 024328 Issue: 2 Pages: 2-19
  • DOI: 10.1103/physrevc.106.024328
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Emission of single and few electrons in XENON1T and limits on light dark matter (2022)
  • Author(s): E. Aprile et al. XENON collaboration
  • Journal Title: Physical Review D Volume: 106, 022001 Issue: 2 Pages: 1-21
  • DOI: 10.1103/physrevd.106.022001
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Application and modeling of an online distillation method to reduce krypton and argon in XENON1T (2022)
  • Author(s): E. Aprile et al. XENON collaboration
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 2022 053H01 Pages: 1-21
  • DOI: 10.1093/ptep/ptac074
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] 222Rn emanation measurements for the XENON1T experiment (2021)
  • Author(s): E. Aprile, ..., Y. Itow, ..., S. Kazama, ..., K. Martens, ..., S. Moriyama, ..., A. Takeda, ..., et. al. (XENON Collaboration)
  • Journal Title: Eur. Phys. J. C 81:337 (2021) pp1-14 Volume: C 81:337 Issue: 4 Pages: 1-14
  • DOI: 10.1140/epjc/s10052-020-08777-z
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Search for inelastic scattering of WIMP dark matter in XENON1T (2021)
  • Author(s): E. Aprile, ..., Y. Itow, ..., S. Kazama, ..., K. Martens, ..., S. Moriyama, ..., A. Takeda, ..., et. al. (XENON Collaboration)
  • Journal Title: Physical Review D Volume: 103 Issue: 6 Pages: 063028-063028
  • DOI: 10.1103/physrevd.103.063028
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Search for Coherent Elastic Scattering of Solar B8 Neutrinos in the XENON1T Dark Matter Experiment (2021)
  • Author(s): E. Aprile, ..., Y. Itow, ..., S. Kazama, ..., K. Martens, ..., S. Moriyama, ..., A. Takeda, ..., et. al. (XENON Collaboration)
  • Journal Title: Physical Review Letters Volume: 126 Issue: 9 Pages: 091301-091301
  • DOI: 10.1103/physrevlett.126.091301
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] The development of Hermetic Quartz Detector for the DARWIN experiment (2024)
  • Author(s): M.Kobayashi
  • Organizer: Nagoya Workshop on Technology and Instrumentation in Future Liquid Noble Gas Detectors
  • Int'l Joint Research / Invited
• [Presentation] キセノンガス中の微量水素量測定法の開発 (2024)
  • Author(s): 小林雅俊
  • Organizer: 日本物理学会2024年春季大会
• [Presentation] XENONnT実験による太陽ニュートリノの探索 (2023)
  • Author(s): 小林雅俊
  • Organizer: 日本物理学会 第78回年次大会
• [Presentation] Activities in Nagoya group (2023)
  • Author(s): M.Kobayashi
  • Organizer: Heavy Flavor and Dark Matter Joint Unit Symposium
  • Int'l Joint Research
• [Presentation] Direct Dark Matter Detection with XENONnT/DARWIN (2023)
  • Author(s): M.Kobayashi
  • Organizer: The 5th KMI International Symposium (KMI2023)
  • Int'l Joint Research / Invited
• [Presentation] DARWIN実験のための新型電極の開発に向けた部材の量子効率測定 (2023)
  • Author(s): 小林雅俊
  • Organizer: 日本物理学会2023年春季大会
• [Presentation] XENONnT実験による太陽ppニュートリノ信号の探索 (2023)
  • Author(s): 小林雅俊
  • Organizer: 日本物理学会2023年春季大会
• [Presentation] The XENONnT experiment: recent status and updates (2022)
  • Author(s): M.Kobayashi
  • Organizer: International Workshop on Applications of Noble Gas Xenon to Science and Technology (XeSAT2022)
  • Int'l Joint Research / Invited
• [Presentation] The development of hermetic quartz chamber for future low background liquid xenon detectors (2022)
  • Author(s): M.Kobayashi
  • Organizer: International Workshop on Applications of Noble Gas Xenon to Science and Technology (XeSAT2022)
  • Int'l Joint Research
• [Presentation] XENONnT：低エネルギー電子反跳バックグラウンドの理解に向けた環境中トリチウムの計測（2） (2022)
  • Author(s): 小林雅俊
  • Organizer: 日本物理学会2022年秋季大会
• [Presentation] XENONnT実験のバックグラウンド理解へ向けた環境中トリチウムの測定 (2022)
  • Author(s): 小林雅俊
  • Organizer: 新学術領域「地下から解き明かす宇宙の歴史と物質の進化」若手研究会
• [Presentation] XENONnT実験: XENON実験全体の現状報告 (2021)
  • Author(s): 小林雅俊
  • Organizer: 日本物理学会2021年秋季大会
• [Remarks] First WIMP Search Results from the XENONnT
  • URL: https://www.kmi.nagoya-u.ac.jp/eng/blog/2023/03/23/2757/
• [Remarks] 暗黒物質探索実験XENONnTによる最初の新物理探索の成果： 電子反跳事象に関する最新観測結果
  • URL: https://www.kmi.nagoya-u.ac.jp/blog/2022/07/22/xenonnt_first_results/