Cosmological determinations of absolute values of neutrino masses

• Project Area: Unification and Development of the Neutrino Science Frontier
• Project/Area Number: 16H00877
• 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: High Energy Accelerator Research Organization
• Principal Investigator: 郡 和範 大学共同利用機関法人高エネルギー加速器研究機構, 素粒子原子核研究所, 准教授 (50565819)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000); Fiscal Year 2017: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2016: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
• Keywords: 宇宙論 / 宇宙物理学 / ニュートリノ / 21cm線 / 宇宙線 / IceCube / 再電離 / 原始ブラックホール

Outline of Annual Research Achievements

将来に計画されている宇宙マイクロ波背景放射(CMB)の偏光観測と宇宙論的な21cm線の観測は、ニュートリノの質量の絶対値にたいへん感度がある。このことは、主に既存のニュートリノ振動実験が質量の２条差に感度があることと比較すると、相補的である。CMBの偏光観測、21cm線観測に加えて、バリオン音響振動(BAO)の観測を組み合わせることが、我々のアイディアである。21cm線とは中性水素の電子のスピンがフリップするときに放射される輝線である。SKAにより、赤方偏移10あたりに起こる再イオン化の時期に放出される宇宙論的な21cmの輝線を精度よく観測すれば、ニュートリノ質量約O(0.01)eVを持つニュートリノが非相対論化し、宇宙膨張を変更する兆候をとらえることができる。また、Simons ArrayによるCMBの偏光観測も上記の範囲のニュートリノ質量に感度がある。さらにパラメーター決定の上での不定性を除くため、ダークマターとダークエネルギー量に感度のあるBAOの将来観測として、DESI実験のデータを加える。我々が発表した文献 (Y. Oyama, K. Kohri and M. Hazumi JCAP 1602 (2016)no.02, 008)により、次の３つの結論が得られた。1)ニュートリノ質量の階層性を決定できる。2)ニュートリの質量の絶対値を0.04 eVの精度で検出できる。3) ニュートリノ有効世代数を0.1世代の精度で検証できる。実際、これらの実験の本観測が始まる前に、準備として、それらの観測機器の仕様についての理論サイドからの提言を続けて行く予定である。現実的にSimons Arrayについての理論提言については、KEKのCMB実験グループとの連携により、共同研究が続けられている (Oyama et al, 2018 in preparation)。

Research Progress Status

29年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

29年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] LAPTh(France)
• [Int'l Joint Research] University of Oxford/Queen Mary University of London(United Kingdom)
• [Int'l Joint Research] Johns Hopkins University/Pensilvania State University(米国)
• [Int'l Joint Research] Institute for Basic Science(韓国)
• [Int'l Joint Research] LAPTh, Universite de Savoie(フランス)
• [Int'l Joint Research] IBS/KIAS(韓国)
• [Int'l Joint Research] 國立台湾大学(台湾)
• [Int'l Joint Research] CTP, Jamia Millia Islamia(インド)
• [Int'l Joint Research] Queen Mary University(英国)
• [Int'l Joint Research]
• [Journal Article] Constraints on small-scale primordial power by annihilation signals from extragalactic dark matter minihalos (2018)
  • Author(s): Tomohiro Nakama, Teruaki Suyama, Kazunori Kohri, and Nagisa Hiroshima
  • Journal Title: Physical Review D Volume: 97 Issue: 2 Pages: 1-7
  • DOI: 10.1103/physrevd.97.023539
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Revisiting big-bang nucleosynthesis constraints on long-lived decaying particles (2018)
  • Author(s): Kawasaki Masahiro、Kohri Kazunori、Moroi Takeo、Takaesu Yoshitaro
  • Journal Title: Physical Review D Volume: 97 Issue: 2 Pages: 023502-023502
  • DOI: 10.1103/physrevd.97.023502
  • Peer Reviewed / Open Access
• [Journal Article] High-energy neutrinos from multibody decaying dark matter (2018)
  • Author(s): Hiroshima Nagisa、Kitano Ryuichiro、Kohri Kazunori、Murase Kohta
  • Journal Title: Physical Review D Volume: 97 Issue: 2 Pages: 023006-023006
  • DOI: 10.1103/physrevd.97.023006
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] CMB bounds on disk-accreting massive primordial black holes (2017)
  • Author(s): Vivian Poulin, Pasquale D. Serpico, Francesca Calore, Sebastien Clesse, and Kazunori Kohri
  • Journal Title: Physical Review D Volume: 96 Issue: 8 Pages: 083524-083524
  • DOI: 10.1103/physrevd.96.083524
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Spins of primordial black holes formed in the matter-dominated phase of the Universe (2017)
  • Author(s): Tomohiro Harada, Chul-Moon Yoo, Kazunori Kohri, Ken-ichi Nakao
  • Journal Title: Physical Review D Volume: 96 Issue: 8 Pages: 083517-083517
  • DOI: 10.1103/physrevd.96.083517
  • Peer Reviewed / Open Access
• [Journal Article] Can decaying particle explain cosmic infrared background excess? (2017)
  • Author(s): Kohri Kazunori、Moroi Takeo、Nakayama Kazunori
  • Journal Title: Physics Letters B Volume: 772 Pages: 628-633
  • DOI: 10.1016/j.physletb.2017.07.026
  • Peer Reviewed / Open Access
• [Journal Article] Multi-field effects in a simple extension of R2 inflation (2017)
  • Author(s): Mori Taro、Kohri Kazunori、White Jonathan
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 2017 Issue: 10 Pages: 044-044
  • DOI: 10.1088/1475-7516/2017/10/044
  • Peer Reviewed / Open Access
• [Journal Article] Axion-like particles and recent observations of the cosmic infrared background radiation (2017)
  • Author(s): Kazunori Kohri and Hideo Kodama
  • Journal Title: Physical Review D Volume: 96 Issue: 5 Pages: 051701-051701
  • DOI: 10.1103/physrevd.96.051701
  • Peer Reviewed / Open Access
• [Journal Article] Constraints on long-lived electrically charged massive particles from anomalous strong lens systems (2017)
  • Author(s): Kamada Ayuki、Inoue Kaiki Taro、Kohri Kazunori、Takahashi Tomo
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 2017 Issue: 11 Pages: 008-008
  • DOI: 10.1088/1475-7516/2017/11/008
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Cosmological constant problem and renormalized vacuum energy density in curved background (2017)
  • Author(s): Kohri Kazunori、Matsui Hiroki
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 2017 Issue: 06 Pages: 006-006
  • DOI: 10.1088/1475-7516/2017/06/006
  • Peer Reviewed / Open Access
• [Journal Article] Elucidating Dark Energy with Future 21 cm Observations at the Epoch of Reionization (2017)
  • Author(s): K.~Kohri, Y.~Oyama, T.~Sekiguchi and T.~Takahashi,
  • Journal Title: JCAP Volume: 02 Issue: 02 Pages: 24-24
  • DOI: 10.1088/1475-7516/2017/02/024
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Effects of electrically charged dark matter on cosmic microwave background anisotropies (2017)
  • Author(s): A.~Kamada, K.~Kohri, T.~Takahashi and N.~Yoshida
  • Journal Title: Phys. Rev. D Volume: 95 Issue: 2 Pages: 023502-023502
  • DOI: 10.1103/physrevd.95.023502
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Primordial black hole formation in the matter-dominated phase of the Universe (2016)
  • Author(s): T.~Harada, C.~M.~Yoo, K.~Kohri, K.~i.~Nakao and S.~Jhingan
  • Journal Title: Astrophysical Journal Volume: 833 Issue: 1 Pages: 61-61
  • DOI: 10.3847/1538-4357/833/1/61
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] LiteBIRD: Mission Overview and Focal Plane Layout (2016)
  • Author(s): T. Matsumura , Y. Akiba, K. Arnold, J. Borrill, R. Chendra, Y. Chinone, A. Cukierman, T. de Haan, M. Dobbs, A. Dominjon, T. Elleflot, J. Errard, T. Fujino, H. Fuke, N. Goeckner-wald, N. Halverson, P. Harvey, M. Hasegawa, et al.
  • Journal Title: Journal of Low Temperature Physics Volume: 185 Issue: 3-4 Pages: 1-8
  • DOI: 10.1007/s10909-016-1542-8
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Constraints on primordial black holes from the Galactic gamma-ray background (2016)
  • Author(s): B.J. Carr, Kazunori Kohri, Yuuiti Sendouda, Jun'ichi Yokoyama
  • Journal Title: Phys.Rev. D Volume: 94 Issue: 4 Pages: 044029-044029
  • DOI: 10.1103/physrevd.94.044029
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Cosmology with the Square Kilometre Array by SKA-Japan (2016)
  • Author(s): D. Yamauchi, K. Ichik, K. Kohri et al.
  • Journal Title: Publ.Astron.Soc.Jap Volume: 68
  • DOI: 10.1093/pasj/psw098
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Higgs vacuum metastability in primordial inflation, preheating, and reheating (2016)
  • Author(s): Kazunori Kohri, Hiroki Matsui
  • Journal Title: Phys.Rev. D Volume: 94 Issue: 10 Pages: 103509-103509
  • DOI: 10.1103/physrevd.94.103509
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Dynamical fine-tuning of initial conditions for small field inflation (2016)
  • Author(s): Satoshi Iso, Kazunori Kohri, Kengo Shimada
  • Journal Title: Physical Review D93 Volume: no.8 Issue: 8 Pages: 084009-084009
  • DOI: 10.1103/physrevd.93.084009
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Can we explain AMS-02 antiproton and positron excesses simultaneously by nearby supernovae without pulsars nor dark matter? (2016)
  • Author(s): K. Kohri, K. Ioka, Y. Fujita, & R. Yamazaki
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 2016 Issue: 2 Pages: 021E01-021E01
  • DOI: 10.1093/ptep/ptv193
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] What we can learn from the spectral index of the tensor mode (2016)
  • Author(s): K. Kohri, C.M. Lin and T. Matsuda
  • Journal Title: Physics Letters B Volume: 755 Pages: 70-75
  • DOI: 10.1016/j.physletb.2016.01.053
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Presentation] Primordial Black Hole Cosmology (2018)
  • Author(s): 郡 和範
  • Organizer: Seminar in Queen Mary University of London, London (United Kingdom)
  • Invited
• [Presentation] Constraints on decaying/annihilating long-lived particles from big-bang nucleosynthesis (2018)
  • Author(s): 郡 和範
  • Organizer: Cosmology Seminar in LPTHE, University Paris 6, Paris (France)
  • Invited
• [Presentation] 重力波天文学」宇宙初期の重力波 (2017)
  • Author(s): 郡 和範
  • Organizer: 朝日カルチャーセンター湘南 (神奈川県・藤沢市)
  • Invited
• [Presentation] 宇宙のはじまりはいつ？ (2017)
  • Author(s): 郡 和範
  • Organizer: 全国同時七夕講演会つくば (茨城県・つくば市)
  • Invited
• [Presentation] Primordial Black Hole Cosmology (2017)
  • Author(s): 郡 和範
  • Organizer: Cosmology Seminar, Jyvaskyla (Finland)
  • Invited
• [Presentation] Revisiting Big-Bang Nucleosynthesis Constraints on Decaying Particles (2017)
  • Author(s): 郡 和範
  • Organizer: Cosmology Seminar, Jyvaskyla (Finland)
  • Invited
• [Presentation] Primordial Black Hole Cosmology (2017)
  • Author(s): 郡 和範
  • Organizer: Mathematical Science Seminar, Sussex (United Kingdom)
  • Invited
• [Presentation] Primordial Black Hole Cosmology (2017)
  • Author(s): 郡 和範
  • Organizer: Dalitz Seminar in Fundamental Physics, Oxford (United Kingdom)
  • Invited
• [Presentation] Primordial Black Hole Cosmology (2017)
  • Author(s): 郡 和範
  • Organizer: Particle Physics Seminar, Liverpool (United Kingdom)
  • Invited
• [Presentation] Primordial Black Hole Cosmology (2017)
  • Author(s): 郡 和範
  • Organizer: HEPHY Cosmology Seminar, Vienna (Austria)
  • Invited
• [Presentation] 宇宙線観測と素粒子物理学 (2017)
  • Author(s): 郡 和範
  • Organizer: 日本物理学会シンポジウム「宇宙線直接観測の成果と展望」
  • Place of Presentation: 大阪大学豊中キャンパス (大阪府・豊中市)
  • Invited
• [Presentation] DM間接検出の理論のレビュー (2017)
  • Author(s): 郡 和範
  • Organizer: CRC タウンミーティング
  • Place of Presentation: 東大柏の葉キャンパス (千葉県・柏市)
  • Invited
• [Presentation] 素粒子論的宇宙論 (2016)
  • Author(s): 郡 和範
  • Organizer: 大阪市大理学部物理学科集中講義
  • Place of Presentation: 大阪市大理学部物理学科 (大阪府・大阪市)
  • Year and Date: 2016-10-17
  • Invited
• [Presentation] 宇宙の誕生とインフレーション第1回ビッグバン宇宙モデル (2016)
  • Author(s): 郡 和範
  • Organizer: 朝日カルチャーセンター湘南
  • Place of Presentation: ルミネ藤沢 (神奈川県・藤沢市)
  • Invited
• [Presentation] Higgs vacuum metastability in inflation, preheating, and reheating (2016)
  • Author(s): 郡 和範
  • Organizer: 立教大宇宙物理学セミナー
  • Place of Presentation: 立教大 (東京都・豊島区)
  • Invited
• [Presentation] Higgs vacuum metastability in inflation, preheating, and reheating (2016)
  • Author(s): 郡 和範
  • Organizer: The First KEKKIAS-NCTS Joint Workshop on Particle Physics Phenomenology
  • Place of Presentation: Hsinchu (Taiwan)
  • Int'l Joint Research / Invited
• [Presentation] 宇宙の誕生とインフレーション第2 回インフレーション宇宙の最前線 (2016)
  • Author(s): 郡 和範
  • Organizer: 朝日カルチャーセンター湘南
  • Place of Presentation: ルミネ藤沢 (神奈川県・藤沢市)
  • Invited
• [Presentation] 「宇宙のはじまりに迫る」第4 回ビッグバン宇宙とインフレーション (2016)
  • Author(s): 郡 和範
  • Organizer: 朝日カルチャーセンター横浜
  • Place of Presentation: ルミネ横浜 (神奈川県・横浜市)
  • Invited
• [Presentation] 「夜空のムコウー重力波ってなに？ー」お話その1「宇宙からやってくる重力波」 (2016)
  • Author(s): 郡 和範
  • Organizer: 全国同時七夕講演会つくば
  • Place of Presentation: つくばエキスポセンター (茨城県・つくば市)
  • Invited
• [Presentation] Cosmology with charged massive particles (2016)
  • Author(s): 郡 和範
  • Organizer: The KEK-Fermilab joint semiar
  • Place of Presentation: Batavia ( USA)
  • Int'l Joint Research / Invited
• [Presentation] 「ビッグバン元素合成」元素はどのように生まれてきたのか？ (2016)
  • Author(s): 郡 和範
  • Organizer: 朝日カルチャーセンター湘南
  • Place of Presentation: ルミネ湘南 (神奈川県・藤沢市)
  • Invited
• [Presentation] Higgs vacuum metastability in primordial inflation, preheating, and reheating (2016)
  • Author(s): 郡 和範
  • Organizer: 大阪市大理学部物理学科談話会
  • Place of Presentation: 大阪市大理学部物理学科 (大阪府・大阪市)
  • Invited
• [Presentation] 将来の21cm線観測と新しい物理学 (2016)
  • Author(s): 郡 和範
  • Organizer: 初代星・初代銀河研究会2016
  • Place of Presentation: 金沢大学 (石川県・金沢市)
  • Invited
• [Presentation] Dark matter in cosmology (2016)
  • Author(s): 郡 和範
  • Organizer: DBD16 workshop
  • Place of Presentation: 大阪吹田キャンパス (大阪府・吹田市)
  • Int'l Joint Research / Invited
• [Presentation] Recent IR background observations and axion-photon conversions (2016)
  • Author(s): 郡 和範
  • Organizer: YITP UTQuest5 workshop
  • Place of Presentation: 京大基礎物理学研究所 (京都府・京都市)
  • Int'l Joint Research / Invited
• [Remarks] International Workshop KEK-Cosmo 2017
  • URL: http://research.kek.jp/people/kohri/KEKCosmo2017.pdf
• [Funded Workshop] KEK-Cosmo 2018 (2018)
• [Funded Workshop] KEK-Cosmo 2017 (2017)
  • Place of Presentation: KEKつくばキャンパス (茨城県・つくば市)
  • Year and Date: 2017-02-20
• [Funded Workshop] KEK-Cosmo 2017 (2017)