Search for supernova relic neutrinos by improving neutrino neutral current cross section measurement

• Project/Area Number: 17J06141
• Research Category: Grant-in-Aid for JSPS Fellows
• Allocation Type: Single-year Grants
• Section: 国内
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Kyoto University
• Principal Investigator: 芦田 洋輔 京都大学, 理学研究科, 特別研究員(DC1)
• Project Period (FY): 2017-04-26 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥3,100,000 (Direct Cost: ¥3,100,000); Fiscal Year 2019: ¥1,000,000 (Direct Cost: ¥1,000,000); Fiscal Year 2018: ¥1,000,000 (Direct Cost: ¥1,000,000); Fiscal Year 2017: ¥1,100,000 (Direct Cost: ¥1,100,000)
• Keywords: 超新星背景ニュートリノ / ニュートリノ中性カレント弾性散乱反応 / スーパーカミオカンデ / T2K実験 / ミューオンモニター / ニュートリノ中性カレント反応 / 中性子・酸素原子核反応 / ガンマ線

Outline of Annual Research Achievements

本研究の目的は、T2Kビームを用いたニュートリノ中性カレント反応の精密測定、およびその結果を用いたスーパーカミオカンデでの超新星背景ニュートリノの探索感度向上である。
最終年度には、前年度に測定したT2K実験でのニュートリノおよび反ニュートリノと酸素の中性カレント反応断面積の結果を学術論文として公表した。また、国際・国内学会での報告も行った。
そして、研究計画通り、スーパーカミオカンデでの超新星背景ニュートリノ探索解析に着手した。結果として、これまで100%が課されていた大気ニュートリノの中性カレント反応背景事象の系統誤差を60%程度まで低減することに成功した。これにより、超新星背景ニュートリノフラックスの探索感度を12%向上した。さらに、他の背景事象として重要である宇宙線ミューオンによる核破砕事象を精確に評価・削減するための解析フレームワークを一新した。その他、研究代表者は解析に必須となるデータのプロセスおよびモンテカルロシミュレーションの準備までを全て行い、最終結果を出す準備を整えた。そうして得られた探索結果は世界最高精度のものであった。本結果を元に学術論文を公表する予定である。
上記とは独立して、二年目までに行っていたT2K実験ミューオンモニターに関する研究も引き続き行った。本年度は東北大学において電子ビーム照射試験を行い、プロトタイプ検出器が現状のミューオンモニター検出器よりも有望であるとの結果を得た。
研究代表者は上記の研究結果を元に博士学位論文を執筆し、京都大学より博士号を授与された。

Research Progress Status

令和元年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和元年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] エコールポリテクニーク(フランス)
• [Int'l Joint Research] パドバ大学(イタリア)
• [Int'l Joint Research] パドバ大学(イタリア)
• [Int'l Joint Research] TRIUMF(カナダ)
• [Int'l Joint Research] 清華大学(中国)
• [Int'l Joint Research] パドバ大学(イタリア)
• [Int'l Joint Research] TRIUMF/トロント大学(カナダ)
• [Journal Article] Search for proton decay into three charged leptons in 0.37 megaton-years exposure of the Super-Kamiokande (2020)
  • Author(s): Tanaka M et al. (The Super-Kamiokande Collaboration)
  • Journal Title: Physical Review D Volume: 101 Issue: 5 Pages: 1-12
  • DOI: 10.1103/physrevd.101.052011
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Measurement of the muon neutrino charged-current single pi^+ production on hydrocarbon using the T2K off-axis near detector ND280 (2020)
  • Author(s): K. Abe, T. Ishida, Y. Oyama et al.
  • Journal Title: Physical Review D Volume: 101 Issue: 1 Pages: 012007-012007
  • DOI: 10.1103/physrevd.101.012007
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Constraint on the Matter-Antimatter Symmetry-Violating Phase in Neutrino Oscillations (2020)
  • Author(s): Abe K et al. (T2K Collaboration)
  • Journal Title: Nature Volume: 580 Issue: 7803 Pages: 339-339
  • DOI: 10.1038/s41586-020-2177-0
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Search for Electron Antineutrino Appearance in a Long-Baseline Muon Antineutrino Beam (2020)
  • Author(s): Abe K et al. (T2K Collaboration)
  • Journal Title: Physical Review Letters Volume: 124 Issue: 16 Pages: 161802-161802
  • DOI: 10.1103/physrevlett.124.161802
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Measurement of neutrino and antineutrino neutral-current quasielasticlike interactions on oxygen by detecting nuclear deexcitation gamma rays (2019)
  • Author(s): K. Abe, T. Ishida, Y. Oyama et al.
  • Journal Title: Physical Review D Volume: 100 Issue: 11 Pages: 112009-112009
  • DOI: 10.1103/physrevd.100.112009
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Atmospheric neutrino oscillation analysis with improved event reconstruction in Super-Kamiokande IV (2019)
  • Author(s): Jiang M. et al.
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 2019 Issue: 5 Pages: 1-39
  • DOI: 10.1093/ptep/ptz015
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Search for light sterile neutrinos with the T2K far detector Super-Kamiokande at a baseline of 295 km (2019)
  • Author(s): K. Abe, T. Ishida, Y. Oyama et al.
  • Journal Title: Physical Review D Volume: 99 Issue: 7 Pages: 071103-071103
  • DOI: 10.1103/physrevd.99.071103
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Search for neutral-current induced single photon production at the ND280 near detector in T2K (2019)
  • Author(s): K. Abe, T. Ishida, Y. Oyama et al.
  • Journal Title: Journal of Physics G: Nuclear and Particle Physics Volume: 46 Issue: 8 Pages: 8-8
  • DOI: 10.1088/1361-6471/ab227d
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Search for heavy neutrinos with the T2K near detector ND280 (2019)
  • Author(s): Abe K et al. (T2K Collaboration)
  • Journal Title: Physical Review D Volume: 100 Issue: 5 Pages: 052006-052006
  • DOI: 10.1103/physrevd.100.052006
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Measurement of the muon neutrino charged-current cross sections on water, hydrocarbon and iron, and their ratios, with the T2K on-axis detectors (2019)
  • Author(s): K. Abe, T. Ishida, Y. Oyama et al.
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 2019 Issue: 9 Pages: 1-30
  • DOI: 10.1093/ptep/ptz070
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Sensitivity of Super-Kamiokande with Gadolinium to Low Energy Antineutrinos from Pre-supernova Emission (2019)
  • Author(s): Simpson C. et al., the Super-Kamiokande Collaboration
  • Journal Title: The Astrophysical Journal Volume: 885 Issue: 2 Pages: 133-133
  • DOI: 10.3847/1538-4357/ab4883
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Search for Astronomical Neutrinos from Blazar TXS 0506+056 in Super-Kamiokande (2019)
  • Author(s): Hagiwara K. et al. (The Super-Kamiokande Collaboration)
  • Journal Title: The Astrophysical Journal Volume: 887 Issue: 1 Pages: 1-1
  • DOI: 10.3847/2041-8213/ab5863
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Measurement of the neutrino-oxygen neutral-current quasielastic cross section using atmospheric neutrinos at Super-Kamiokande (2019)
  • Author(s): Wan L et al. (Super-Kamiokande Collaboration)
  • Journal Title: Physical Review D Volume: 99 Issue: 3 Pages: 032005-032005
  • DOI: 10.1103/physrevd.99.032005
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Separation of gamma-ray and neutron events with CsI(Tl) pulse shape analysis (2018)
  • Author(s): Ashida Y et al.
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 2018 Issue: 4
  • DOI: 10.1093/ptep/pty040
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A new electron-multiplier-tube-based beam monitor for muon monitoring at the T2K experiment (2018)
  • Author(s): Ashida Y et al.
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 2018 Issue: 10
  • DOI: 10.1093/ptep/pty104
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Measurement of inclusive double-differential nu_mu charged-current cross section with improved acceptance in the T2K off-axis near detector (2018)
  • Author(s): K.Abe, T.Ishida, Y.Oyama et al
  • Journal Title: Physical Review D Volume: 98 Issue: 1 Pages: 012004-012004
  • DOI: 10.1103/physrevd.98.012004
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Characterization of nuclear effects in muon-neutrino scattering on hydrocarbon with a measurement of final-state kinematics and correlations in charged-current pionless interactions at T2K (2018)
  • Author(s): K.Abe, T.Ishida, Y.Oyama et al
  • Journal Title: Physical Review D Volume: 98 Issue: 3 Pages: 032003-032003
  • DOI: 10.1103/physrevd.98.032003
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Physics potentials with the second Hyper-Kamiokande detector in Korea (2018)
  • Author(s): K. Abe, O. Yasuda et al.
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 2018 Issue: 6
  • DOI: 10.1093/ptep/pty044
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Search for CP violation in Neutrino and Antineutrino Oscillations by the T2K experimen with 2.2x10^21 protons on target (2018)
  • Author(s): K.Abe, T.Ishida, Y.Oyama et al
  • Journal Title: Physical Review Letters Volume: 121 Issue: 17 Pages: 171802-171802
  • DOI: 10.1103/physrevlett.121.171802
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] First measurement of the νμ charged-current cross section on a water target without pions in the final state (2018)
  • Author(s): Abe K et al. (T2K Collaboration)
  • Journal Title: Physical Review D Volume: 97 Issue: 1 Pages: 012001-012001
  • DOI: 10.1103/physrevd.97.012001
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Updated T2K measurements of muon neutrino and antineutrino disappearance using 1.5×10^21 protons on target (2017)
  • Author(s): T. Nakaya, T. Nakadaira, A.K. Ichikawa, Y. Seiya 他 (T2K Collaboration 約300名)
  • Journal Title: Phys. Rev. D Volume: 96 Issue: 1 Pages: 011102-011102
  • DOI: 10.1103/physrevd.96.011102
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Measurement of ν￣μ and νμ charged current inclusive cross sections and their ratio with the T2K off-axis near detector (2017)
  • Author(s): Abe K et al. (T2K Collaboration)
  • Journal Title: Physical Review D Volume: 96 Issue: 5 Pages: 052001-052001
  • DOI: 10.1103/physrevd.96.052001
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Measurement of neutrino and antineutrino oscillations by the T2K experiment including a new additional sample of ne interactions at the far detector (2017)
  • Author(s): T. Nakaya, T. Nakadaira, A.K. Ichikawa, Y. Seiya, A. Minamino 他（T2K Collaboration 約300名）
  • Journal Title: Phys. Rev. D Volume: 96 Issue: 9 Pages: 092006-092006
  • DOI: 10.1103/physrevd.96.092006
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Neutrino-oxygen neutral-current elastic interactions as a background in supernova relic neutrino search (2019)
  • Author(s): Y. Ashida
  • Organizer: The 16th International Conference on Topics in Astroparticle and Underground Physics
  • Int'l Joint Research
• [Presentation] Supernova Relic Neutrino Searches (2019)
  • Author(s): 芦田洋輔
  • Organizer: 第26回素粒子国際センターシンポジウム
• [Presentation] スーパーカミオカンデにおける超新星背景ニュートリノ探索 (2019)
  • Author(s): 芦田洋輔、他スーパーカミオカンデコラボレーション
  • Organizer: 第75回日本物理学会年次大会
• [Presentation] T2K 実験-後置検出器におけるニュートリノ-酸素原子核中性カレント弾性散乱反応断面積の測定 (2019)
  • Author(s): 芦田洋輔、他T2K コラボレーション
  • Organizer: 日本物理学会 第74 回年次大会
• [Presentation] 超新星背景ニュートリノ探索における背景事象精密評価のためのニュートリノ-酸素原子核中性カレ ント弾性散乱反応断面積の測定 (2019)
  • Author(s): 芦田洋輔
  • Organizer: 第32 回 超新星背景ニュートリノ研究会
• [Presentation] スーパーカミオカンデにおける中性子・酸素原子核反応シミュレーションの改良 (2018)
  • Author(s): 芦田洋輔、他スーパーカミオカンデコラボレーション
  • Organizer: 日本物理学会 2018 年秋季大会
• [Presentation] T2K 実験ミューオンモニターのための新型検出器・電子増倍管に関する研究 (2018)
  • Author(s): 芦田洋輔、他5 名
  • Organizer: 日本物理学会 2018 年秋季大会
• [Presentation] Improvement of neutron-oxygen reaction model at Super-Kamiokande for neutrino neutral current interaction study (2018)
  • Author(s): Y. Ashida
  • Organizer: The 1st International Symposium on Neutrino Frontiers
  • Int'l Joint Research
• [Presentation] ニュートリノ中性カレント反応精密測定のための核子・酸素原子核反応に関する研究 (結果) (2017)
  • Author(s): 芦田 洋輔 他
  • Organizer: 日本物理学会 2017年秋季大会
• [Presentation] T2K実験ミューオンモニターのための二次電子放出を利用した新型検出器開発 (2017)
  • Author(s): 芦田 洋輔 他
  • Organizer: 日本物理学会 2017年秋季大会
• [Presentation] Measurement of gamma-rays from neutron-oxygen reaction for neutrno-nucleus interaction (2017)
  • Author(s): Ashida Y
  • Organizer: The 10th International Neutrino Summer School (INSS2017)
  • Int'l Joint Research
• [Presentation] J-PARC Nu Muon Monitor (2017)
  • Author(s): Ashida Y
  • Organizer: The 10th International Workshop on Neutrino Beams and Instrumentation (NBI2017)
  • Int'l Joint Research
• [Presentation] Measurement of gamma-rays from neutron-oxygen reaction for neutrno-nucleus interaction (2017)
  • Author(s): Ashida Y
  • Organizer: The 19th International Workshop on Neutrinos from Accelerators (NUFACT2017)
  • Int'l Joint Research