Indirect search for dark matter with fine structures in the cosmic-ray all-electron spectrum

• Project Area: New expansion of particle physics of post-Higgs era by LHC revealing the vacuum and space-time structure
• Project/Area Number: 19H04617
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: The University of Tokyo (2020); Waseda University (2019)
• Principal Investigator: 浅岡 陽一 東京大学, 宇宙線研究所, 特任准教授 (40345054)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥5,590,000 (Direct Cost: ¥4,300,000、Indirect Cost: ¥1,290,000); Fiscal Year 2020: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000); Fiscal Year 2019: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
• Keywords: CALET / 暗黒物質 / 間接探索 / 全電子スペクトル

Outline of Research at the Start

暗黒物質の正体は，初期宇宙の熱平衡状態から膨張・冷却の過程で凍結され残存した未知の素粒子(WIMP) であるという仮説が有力となっている．
国際宇宙ステーション(ISS) に搭載された宇宙線電子望遠鏡CALET は，TeV (10の12乗電子ボルト)以上のエネルギー領域に及ぶ宇宙線の高精度直接観測を継続中である．CALETは，全電子(電子+ 陽電子)及びガンマ線の観測を介して，重い質量をもつ暗黒物質を，その対消滅や崩壊によって生成される二次粒子を検出することで探索する．
本研究では，CALET全電子スペクトルの微細構造に着目して，暗黒物質探索に新たな光を当てることを目的とする．

Outline of Annual Research Achievements

宇宙の27%を占める暗黒物質の正体は，素粒子と宇宙にまたがる大きな謎である．宇宙背景放射や大規模構造の観測から，暗黒物質は初期宇宙の熱平衡状態から膨張・冷却の過程で凍結され残存した未知の素粒子(WIMP)であるという仮説が有力となっている．
宇宙線電子は，ガンマ線や反粒子を含む暗黒物質間接探索の中でも，特に局所宇宙に感度のあるユニークなプローブである．2018年度にPhysical Review Lettersにて発表されたCALET全電子スペクトルには，数百GeV付近と1TeV付近に微細な構造が存在する可能性がある．本研究ではこの着目して，暗黒物質探索に新たな光を当てることを目的としてきた．
2020年度には，前年度に培った共同研究の土台を引き継ぎ，物理的な動機付けがあり，かつ全電子スペクトルの微細構造を暗黒物質起源として説明することができるモデルを構築し，Physical Review Dにて出版した．本論文では，他観測・他実験における制限や銀河内伝播過程の影響を考慮した上で，CALETの全電子スペクトルを暗黒物質探索の観点から解釈している．現状では既に，暗黒物質と原子核の反跳信号を探索する直接観測や，ガンマ線を用いた間接観測により厳しい制限が与えられていることから，特にそれらのチャンネルへのカップリングが抑制されたモデルにおける電子観測の意義について議論している．
それと同時に，国際宇宙ステーションにおける長期安定観測を継続してスペクトルの精度を向上させるため，軌道上運用の継続とそのさらなる安定化を実施した．既に2018年の論文作成時の２倍を超える統計が得られており，全電子スペクトルのさらなる高精度化を目指し，イベント毎の電子陽子識別など，さらに発展した解析方法を開発している．

Research Progress Status

令和2年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和2年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] ACPTP(韓国)
• [Int'l Joint Research] NASA Goddard Space Flight Center/Louisiana State University/Washington University St. Louis(米国)
• [Int'l Joint Research] Pisa University & INFN/Florence University & INFN/IFAC-CNR(イタリア)
• [Journal Article] Cosmic-ray signatures of dark matter from a flavor dependent gauge symmetry model with neutrino mass mechanism (2020)
  • Author(s): Motz Holger、Okada Hiroshi、Asaoka Yoichi、Kohri Kazunori
  • Journal Title: Physical Review D Volume: 102 Issue: 8 Pages: 083019-083019
  • DOI: 10.1103/physrevd.102.083019
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Direct Measurement of the Cosmic-Ray Carbon and Oxygen Spectra from 10??GeV/n to 2.2??TeV/n with the Calorimetric Electron Telescope on the International Space Station (2020)
  • Author(s): Adriani O.、Akaike Y.、Asano K.、Asaoka Y.、Bagliesi M.G.、Berti E.、Bigongiari G.、Binns W.R.、Bongi M.、Brogi P.、Bruno A.、Buckley J.H.、Cannady N.、Castellini G.、Checchia C.、Cherry M.L.、Collazuol G.、Ebisawa K.、Fuke H.、Gonzi S.、Guzik T.G.、Hams T.、Hibino K.、Ichimura M. 他
  • Journal Title: Physical Review Letters Volume: 125 Issue: 25 Pages: 251102-251102
  • DOI: 10.1103/physrevlett.125.251102
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Direct Measurement of the Cosmic-Ray Proton Spectrum from 50 GeV to 10 TeV with the Calorimetric Electron Telescope on the International Space Station (2019)
  • Author(s): O,Adriani, Y.Asaoka, M.Mori, S.Torii et al. (CALET Collaboration)
  • Journal Title: Physical Review Letters Volume: 122 Issue: 18 Pages: 181102-181102
  • DOI: 10.1103/physrevlett.122.181102
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Measurements of Heavy Cosmic-Ray Nuclei Spectra with CALET on the ISS (2019)
  • Author(s): Y.Akaike et al. (CALET Collaboration)
  • Journal Title: Journal of Physics: Conf. Series (26th Extended European Cosmic Ray Symposium) Volume: 1181 Pages: 012042-012042
  • DOI: 10.1088/1742-6596/1181/1/012042
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The CALorimetric Electron Telescope (CALET) on the International Space Station: Results from the First Two Years (2019)
  • Author(s): Y Asaoka et al. (CALET Collaboration)
  • Journal Title: Journal of Physics: Conf. Series (26th Extended European Cosmic Ray Symposium) Volume: 1181 Pages: 012003-012003
  • DOI: 10.1088/1742-6596/1181/1/012003
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The CALorimetric Electron Telescope (CALET) on the International Space Station (2019)
  • Author(s): Shoji Torii and Pier Simone Marrocchesi for the CALET collaboration
  • Journal Title: Advances in Space Research Volume: 64 Issue: 12 Pages: 2531-2537
  • DOI: 10.1016/j.asr.2019.04.013
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Measurement of cosmic-ray carbon and oxygen energy spectra with CALET (2019)
  • Author(s): Paolo Maestro for the CALET collaboration
  • Journal Title: Advances in Space Research Volume: 64
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The CALorimetric Electron Telescope (CALET) on the International Space Station: Results from the First Two Years of Operation (2019)
  • Author(s): Asaoka Y., et al., CALET Collaboration
  • Journal Title: EPJ Web of Conferences Volume: 208
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Radiation dose during relativistic electron precipitation events at the International Space Station (2019)
  • Author(s): Ueno H., Nakahira S., Kataoka R., Asaoka Y., Torii S., Ozawa S., Matsumoto H., Bruno A., Nolfo G.A., Collazuol G., Ricciarini S.B.
  • Journal Title: Space Weather Volume: - Pages: 209431-7
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] An interpretation of the cosmic ray e+ + e- spectrum from 10 GeV to 3 TeV measured by CALET on the ISS (2019)
  • Author(s): Bhattacharyya Saptashwa, Motz Holger, Asaoka Yoichi, Torii Shoji
  • Journal Title: International Journal of Modern Physics D Volume: 28 Pages: 1950035-1950035
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The CALorimetric Electron Telescope (CALET) on the International Space Station (2019)
  • Author(s): Y. Asaoka et al. (CALET Collaboration)
  • Journal Title: Proceedings of Science (ICRC2019) Volume: 358 Pages: 0011-16
  • Open Access / Int'l Joint Research
• [Journal Article] Measurements of Heavy Cosmic Ray Nuclei Fluxes with CALET (2019)
  • Author(s): Y.Akaike et al. (CALET Collaboration)
  • Journal Title: Proceedings of Science (ICRC2019) Volume: 358 Pages: 0341-8
  • Open Access / Int'l Joint Research
• [Journal Article] Measurement of the Proton Spectrum with CALET on the ISS (2019)
  • Author(s): P.S.Morrocchesi et al. (CALET Collaboration)
  • Journal Title: Proceedings of Science (ICRC2019) Volume: 358 Pages: 1031-8
  • Open Access / Int'l Joint Research
• [Journal Article] Analysis of CALET Data for Anisotropy in Electron+Positron Cosmic Rays (2019)
  • Author(s): H.Motz and Y.Asaoka (CALET Collaboration)
  • Journal Title: Proceeding of Science (ICRC2019) Volume: 358 Pages: 1121-8
  • Open Access / Int'l Joint Research
• [Journal Article] CALET Ultra Heavy Cosmic Ray Observations on the ISS (2019)
  • Author(s): B. F. Rauch, W. Binns et al. (CALET Collaboration)
  • Journal Title: Proceeding of Science (ICRC2019) Volume: 358 Pages: 1301-8
  • Open Access / Int'l Joint Research
• [Journal Article] Extended Measurement of Cosmic-Ray Electron and Positron Spectrum from CALET on the ISS (2019)
  • Author(s): S.Torii et al. (CALET Collaboration)
  • Journal Title: Proceeding of Science (ICRC2019) Volume: 358 Pages: 1421-8
  • Open Access / Int'l Joint Research
• [Journal Article] Interpretation of the CALET Electron+Positron Spectrum concerning Dark Matter Signatures (2019)
  • Author(s): H. Motz, Y. Asaoka and S. Bhattacharyya
  • Journal Title: Proceeding of Science (ICRC2019) Volume: 358 Pages: 5331-8
  • Open Access / Int'l Joint Research
• [Presentation] CALETによる10GeV/nから2.2TeV/nの炭素と酸素のエネルギースクトル観測結果 (2021)
  • Author(s): 赤池陽水
  • Organizer: 日本物理学会第76回年次大会
• [Presentation] CALETによる5年間の観測の進展と運用の報告 (2021)
  • Author(s): 田村忠久
  • Organizer: 日本物理学会第76回年次大会
• [Presentation] CALETによる5年間の軌道上観測の成果と展望 (2021)
  • Author(s): 鳥居祥二
  • Organizer: 日本物理学会第76回年次大会
• [Presentation] CALORIMETRIC ELECTRON TELESCOPE (CALET) ON THE INTERNATIONAL SPACE STATION (2021)
  • Author(s): Shoji Torii
  • Organizer: 43rd COSPAR Scientific Assembly (online)
  • Int'l Joint Research / Invited
• [Presentation] CALETによる宇宙線原子核のエネルギースペクトルの観測 (2021)
  • Author(s): 赤池陽水
  • Organizer: 第21回宇宙科学シンポジウム（オンライン開催）
• [Presentation] CALETによる5年間の観測の進展状況と運用の概要 (2021)
  • Author(s): 田村忠久
  • Organizer: 第21回宇宙科学シンポジウム（オンライン開催）
• [Presentation] 国際宇宙ステーション搭載CALETによる５年間観測の成果 (2021)
  • Author(s): 鳥居祥二
  • Organizer: 第21回宇宙科学シンポジウム（オンライン開催）
• [Presentation] Dark matter from a flavor dependent gauge symmetry model and its signatures in cosmic rays (2020)
  • Author(s): Holger Motz
  • Organizer: KASHIWA DARK MATTER SYMPOSIUM 2020
  • Int'l Joint Research
• [Presentation] CALETによる4.5年間の軌道上観測の最新成果 (2020)
  • Author(s): 鳥居祥二
  • Organizer: 日本物理学会第75回年次大会（2020) オンライン
• [Presentation] CALET：4年半にわたる軌道上運用のまとめ (2020)
  • Author(s): 浅岡陽一
  • Organizer: 日本物理学会第75回年次大会（2020) オンライン
• [Presentation] CALETによる原子核エネルギースペクトルの観測 (2020)
  • Author(s): 赤池陽水
  • Organizer: 日本物理学会第75回年次大会（2020) オンライン
• [Presentation] 国際宇宙ステーション搭載CALETの最新成果 (2020)
  • Author(s): 鳥居祥二
  • Organizer: 第20回宇宙科学シンポジウム, 宇宙科学研究所, 相模原
• [Presentation] CALETの運用状況と電子、陽子・原子核スペクトル (2020)
  • Author(s): 浅岡陽一
  • Organizer: 第20回宇宙科学シンポジウム, 宇宙科学研究所, 相模原
• [Presentation] High Energy Gamma-rays and Gamma-ray Bursts Observations by CALET (2020)
  • Author(s): T. Sakamoto
  • Organizer: 第20回宇宙科学シンポジウム, 宇宙科学研究所, 相模原
• [Presentation] CALET: Calorimetric Electron Telescope (2019)
  • Author(s): Pier Simone Marrocchesi
  • Organizer: XSCRC2019: Cross sections for Cosmic Rays, CERN, Geneva, Switzerland
  • Int'l Joint Research / Invited
• [Presentation] Recent Results and Dark Matter Search with CALET on the ISS (2019)
  • Author(s): Yoichi Asaoka
  • Organizer: Dark Matter searches in the 2020s - At the crossroads of the WIMP, ICRR, University of Tokyo, Kashiwa, Japan
  • Int'l Joint Research / Invited
• [Presentation] CALET Results after Three Years on the International Space Station (2019)
  • Author(s): Yoichi Asaoka
  • Organizer: 16th International Conference on Topics in Astroparticle and Underground Physics, Toyama, Japan
  • Int'l Joint Research
• [Presentation] Calorimetric Electron Telescope on the International Space Station (2019)
  • Author(s): Shoji Torii
  • Organizer: Calorimetry for the High Energy Frontier: CHEF2019, Kyushu Univ. Fukuoka, Japan
  • Int'l Joint Research / Invited
• [Presentation] CALET on the International Space Station: the First Three Years of Operations (2019)
  • Author(s): Paolo Brogi
  • Organizer: 8th International Conference on New Frontiers in Physics (ICNFP2019), Crete, Greece
  • Int'l Joint Research
• [Presentation] The CALorimetric Electron Telescope (CALET) on the International Space Station (2019)
  • Author(s): Yoichi Asaoka
  • Organizer: ICRC2019: 36th International Cosmic Ray Conference, Madison, WI, USA
  • Int'l Joint Research / Invited
• [Presentation] Interpretation of the CALET Electron+Positron Spectrum concerning Dark Matter Signatures (2019)
  • Author(s): Holger Motz
  • Organizer: ICRC2019: 36th International Cosmic Ray Conference, Madison, WI, USA
  • Int'l Joint Research
• [Presentation] Measurements of Heavy Cosmic Ray Nuclei Fluxes with CALET (2019)
  • Author(s): Yosui Akaike
  • Organizer: ICRC2019: 36th International Cosmic Ray Conference, Madison, WI, USA
  • Int'l Joint Research
• [Presentation] Measurement of the Proton Spectrum with CALET on the ISS (2019)
  • Author(s): Pier Simone Marrocchesi
  • Organizer: ICRC2019: 36th International Cosmic Ray Conference, Madison, WI, USA
  • Int'l Joint Research
• [Presentation] Analysis of CALET Data for Anisotropy in Electron+Positron Cosmic Rays (2019)
  • Author(s): Holger Motz
  • Organizer: ICRC2019: 36th International Cosmic Ray Conference, Madison, WI, USA
  • Int'l Joint Research
• [Presentation] CALET Ultra Heavy Cosmic Ray Observations on the ISS (2019)
  • Author(s): Brian F. Rauch
  • Organizer: ICRC2019: 36th International Cosmic Ray Conference, Madison, WI, USA
  • Int'l Joint Research
• [Presentation] Extended Measurement of Cosmic-Ray Electron and Positron Spectrum from CALET on the ISS (2019)
  • Author(s): Shoji Torii
  • Organizer: ICRC2019: 36th International Cosmic Ray Conference, Madison, WI, USA
  • Int'l Joint Research
• [Presentation] An Overview of CALET Observations after 3 Years on ISS (2019)
  • Author(s): Pier Simone Marrocchesi
  • Organizer: EPS-HEP2019: European Physical Society Conference on High Energy Physics, Ghent, Belgium
  • Int'l Joint Research
• [Presentation] CALET Results after Three Years on Orbit on the International Space Station (2019)
  • Author(s): Paolo Maestro
  • Organizer: ISCRA2019: International Sympsium on Cosmic Rays and Astrophysics, MEPhI, Moscow, Russia
  • Int'l Joint Research / Invited
• [Presentation] Calorimetric Electron Telescope (2019)
  • Author(s): Pier Simone Marrocchesi
  • Organizer: Next Generation of Astroparticle Experiments in Space (NextGapes-2019) , Moscow, Russia
  • Int'l Joint Research / Invited
• [Presentation] CALETによる軌道上観測の最新成果 (2019)
  • Author(s): 鳥居祥二
  • Organizer: 日本物理学会2019年秋季大会 山形大学
• [Presentation] CALETによる宇宙線直接観測：陽子スペクトルの漸次的な硬化の高精度検出 (2019)
  • Author(s): 浅岡陽一
  • Organizer: 日本物理学会2019年秋季大会 山形大学
• [Presentation] CALETによる炭素と酸素のエネルギースペクトル測定 (2019)
  • Author(s): 赤池陽水
  • Organizer: 日本物理学会2019年秋季大会 山形大学
• [Presentation] Search for Anisotropy in Electron+Positron Cosmic Rays using CALET Data (2019)
  • Author(s): Holger Motz
  • Organizer: 日本物理学会2019年秋季大会 山形大学
• [Presentation] 宇宙線直接観測と暗黒物質の間接探索 (2019)
  • Author(s): 浅岡陽一
  • Organizer: ダークマターの懇談会 早稲田大学
  • Invited
• [Remarks] CALET-カロリメータ型宇宙電子線望遠鏡
  • URL: https://calet.jp
• [Remarks] DARTS/CALET at ISAS/JAXA
  • URL: http://darts.jaxa.jp/astro/calet
• [Remarks] 高エネルギー電子・ガンマ線観測装置（CALET)
  • URL: https://iss.jaxa.jp/kiboexp/equipment/ef/calet