Cosmology of neutrino oscillation in the early Universe

2020 Fiscal Year Annual Research Report

• Project Area: Exploration of Particle Physics and Cosmology with Neutrinos
• Project/Area Number: 19H05114
• 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): 2019-04-01 – 2021-03-31
• Keywords: ニュートリノ / 初期宇宙 / ビッグバン元素合成 / 宇宙マイクロ波背景放射

Outline of Annual Research Achievements

Holger Motz, et al, Phys. Rev. D 102, 083019 (2020)において、ニュートリノの質量を生む素粒子論モデルの宇宙論的な検証方法の提案を行った。U(1)_{e－μ}というフレーバー依存するU(1)ゲージ理論を含む、U(1)_{e－μ}×Z_3×Z_2というゲージ群の対称性の下で、2ループの効果により、ニュートリノの第1,2世代に質量を持たせるモデルである。このモデルにおいて予言される一番軽い中性ディラックフェルミ粒子はダークマターの候補となり、タウレプトンとの結合が極めて弱いためさまざまな実験からの制限を逃れているという特徴がある。今回、銀河中でのダークマター対消滅における電子陽電子対生成により宇宙線実験における陽電子観測の実験値からのさらなる制限を議論した。このモデルにおいて対消滅断面積にブライトーウイグナー型の共鳴機構が働いて対消滅断面積のCMB観測による上限をさけつつCALET実験の電子+陽電子の過剰シグナルを説明できることを明らかにした。

Takuya Hasegawa, et al, JCAP 08 (2020) 015でインフレーション後の宇宙の最高温度が数MeVであるシナリオにおいて標準理論の左巻き3世代ニュートリノに右巻きのニュートリノが混合している場合、右巻きニュートリノはニュートリノ振動のみでつくられるが熱化しない。そのためビッグバン元素合成と宇宙マイクロ波背景放射に影響することなくその存在が許される可能性がある。インフラトン場が100％電磁的な粒子に壊れる場合、再加熱温度が5MeV程度であればそうした宇宙論的な制限に抵触せずLSNDをはじめとする短いベースラインでのニュートリノ振動実験などで示唆されている質量約1eV程度の右巻きニュートリノの混合角などの性質と無矛盾であることを示した。

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] LAPTh, Annecy/Montpellier/Paris No.7 U(フランス)
  • Country Name: FRANCE
  • Counterpart Institution: LAPTh, Annecy/Montpellier/Paris No.7 U
  • # of Other Institutions: 3
• [Int'l Joint Research] Queen Mary, U of London/Oxford U/Leeds U(英国)
  • Country Name: UNITED KINGDOM
  • Counterpart Institution: Queen Mary, U of London/Oxford U/Leeds U
  • # of Other Institutions: 2
• [Int'l Joint Research] Max Planck Inst./Bonn U(ドイツ)
  • Country Name: GERMANY
  • Counterpart Institution: Max Planck Inst./Bonn U
• [Int'l Joint Research] IBS, Daejeon/APCTP, Pohang(韓国)
  • Country Name: KOREA (REP. OF KOREA)
  • Counterpart Institution: IBS, Daejeon/APCTP, Pohang
• [Int'l Joint Research] Aarhus U./Bohr Inst.(デンマーク)
  • Country Name: DENMARK
  • Counterpart Institution: Aarhus U./Bohr Inst.
• [Int'l Joint Research]
  • # of Other Countries: 11
• [Journal Article] Spins of Primordial Black Holes Formed in the Radiation-dominated Phase of the Universe: First-order Effect (2021)
  • Author(s): Harada Tomohiro、Yoo Chul-Moon、Kohri Kazunori、Koga Yasutaka、Monobe Takeru
  • Journal Title: The Astrophysical Journal Volume: 908 Pages: 140～140
  • DOI: 10.3847/1538-4357/abd9b9
  • Peer Reviewed / Open Access
• [Journal Article] Sensitivity of the Cherenkov Telescope Array for probing cosmology and fundamental physics with gamma-ray propagation (2021)
  • Author(s): H. Abdalla et al
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 2021 Pages: 048～048
  • DOI: 10.1088/1475-7516/2021/02/048
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Solar-mass primordial black holes explain NANOGrav hint of gravitational waves (2021)
  • Author(s): Kohri Kazunori、Terada Takahiro
  • Journal Title: Physics Letters B Volume: 813 Pages: 136040～136040
  • DOI: 10.1016/j.physletb.2020.136040
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Sensitivity of the Cherenkov Telescope Array to a dark matter signal from the Galactic centre (2021)
  • Author(s): A. Acharyya et al
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 2021 Pages: 057～057
  • DOI: 10.1088/1475-7516/2021/01/057
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The First Three Seconds: a Review of Possible Expansion Histories of the Early Universe (2021)
  • Author(s): A. Rouzbeh et al
  • Journal Title: The Open Journal of Astrophysics Volume: 4 Pages: 2021
  • DOI: 10.21105/astro.2006.16182
  • 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): O. Adriani et al, the CALET Collaboration
  • Journal Title: Physical Review Letters Volume: 125 Pages: 251102
  • DOI: 10.1103/PhysRevLett.125.251102
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Abundance of primordial black holes in peak theory for an arbitrary power spectrum (2020)
  • Author(s): Yoo Chul-Moon、Harada Tomohiro、Hirano Shin’ichi、Kohri Kazunori
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 2021 Pages: 1300
  • DOI: 10.1093/ptep/ptaa155
  • Peer Reviewed / Open Access
• [Journal Article] Constraints on electron-scattering interpretation of XENON1T excess (2020)
  • Author(s): Chigusa So、Endo Motoi、Kohri Kazunori
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 2020 Pages: 035～035
  • DOI: 10.1088/1475-7516/2020/10/035
  • Peer Reviewed / Open Access
• [Journal Article] Big-bang nucleosynthesis with sub-GeV massive decaying particles (2020)
  • Author(s): Kawasaki Masahiro、Kohri Kazunori、Moroi Takeo、Murai Kai、Murayama Hitoshi
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 2020 Pages: 048～048
  • DOI: 10.1088/1475-7516/2020/12/048
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] CALET on the International Space Station: the first three years of observations (2020)
  • Author(s): P. Brogi et al
  • Journal Title: Physica Scripta Volume: 95 Pages: 074012～074012
  • DOI: 10.1088/1402-4896/ab957d
  • Peer Reviewed / Open Access / Int'l Joint Research
• [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 Pages: 83019
  • DOI: 10.1103/PhysRevD.102.083019
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Inflaton as the Affleck-Dine baryogenesis field in hilltop supernatural inflation (2020)
  • Author(s): Lin Chia-Min、Kohri Kazunori
  • Journal Title: Physical Review D Volume: 102 Pages: 43511
  • DOI: 10.1103/PhysRevD.102.043511
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] MeV-scale reheating temperature and cosmological production of light sterile neutrinos (2020)
  • Author(s): Hasegawa Takuya、Hiroshima Nagisa、Kohri Kazunori、Hansen Rasmus S.L.、Tram Thomas、Hannestad Steen
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 2020 Pages: 015～015
  • DOI: 10.1088/1475-7516/2020/08/015
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] CALET results after three years on the International Space Station (2020)
  • Author(s): Y. Asaoka et al
  • Journal Title: Journal of Physics: Conference Series Volume: 1468 Pages: 012074～012074
  • DOI: 10.1088/1742-6596/1468/1/012074
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Cosmic microwave background bounds on primordial black holes including dark matter halo accretion (2020)
  • Author(s): Serpico Pasquale D.、Poulin Vivian、Inman Derek、Kohri Kazunori
  • Journal Title: Physical Review Research Volume: 2 Pages: 23204
  • DOI: 10.1103/PhysRevResearch.2.023204
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] LiteBIRD satellite: JAXA's new strategic L-class mission for all-sky surveys of cosmic microwave background polarization (2020)
  • Author(s): M. Hazumi et al
  • Journal Title: Proc. of SPIE Volume: 11443 Pages: 114432F
  • DOI: 10.1117/12.2563050
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Concept design of low frequency telescope for CMB B-mode polarization satellite LiteBIRD (2020)
  • Author(s): Y. Sekimoto et al
  • Journal Title: Proc. of SPIE Volume: 11453 Pages: 1145310
  • DOI: 10.1117/12.2561841
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Overview of the medium and high frequency telescopes of the LiteBIRD space mission (2020)
  • Author(s): Montier Ludovic et al
  • Journal Title: Proc. of SPIE Volume: 11443 Pages: 14432G
  • DOI: 10.1117/12.2562243
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Cosmological accretion on to the primordial black hole + CDM halo system (2020)
  • Author(s): Kazunori Kohri
  • Organizer: 天体形成研究会2020 Online, 筑波大宇宙物理理論研究室
  • Invited
• [Presentation] Primordial black holes and stochastic gravitational wave background reported by NANOGrav 12.5yr (2020)
  • Author(s): Kazunori Kohri
  • Organizer: AAPPS-DACG Workshop on Astrophysics, Cosmology and Gravitation Online
  • Int'l Joint Research
• [Presentation] Primordial black holes and stochastic gravitational wave background reported by NANOGrav 12.5yr (2020)
  • Author(s): Kazunori Kohri
  • Organizer: JGRG 2020 Online
  • Int'l Joint Research
• [Presentation] Solar-Mass Primordial Black Holes Explain NANOGrav Hint of Gravitational Waves (2020)
  • Author(s): Kazunori Kohri
  • Organizer: The 26th KAGRA Face-to-Face meeting in remote style, Session 02 / 13:30-14:30 JST/ Plenary / Contribution talks, Academia Sinica, Taiwan
  • Int'l Joint Research
• [Presentation] Formations of primordial black holes in the early matter-dominated Universe (2020)
  • Author(s): Kazunori Kohri
  • Organizer: Cosmology Seminar Online, Helsinki University
  • Int'l Joint Research / Invited
• [Presentation] Series: What is the spacetime of the Universe? 1st: Cosmology online (2020)
  • Author(s): 郡和範
  • Organizer: 朝日カルチャーセンター藤沢
  • Invited
• [Presentation] Series: What is the spacetime of the Universe?, ``2nd: Inflation online (2020)
  • Author(s): 郡和範
  • Organizer: 朝日カルチャーセンター藤沢
  • Invited
• [Presentation] KAGRA, ``4th: Gravitational wave from the early Universe (2020)
  • Author(s): 郡和範
  • Organizer: 朝日カルチャーセンター新宿
  • Invited
• [Presentation] What is the spacetime of the Universe?, ``3rd: ``Carrying out research examining the past, present, and future of the Universe (2020)
  • Author(s): 郡和範
  • Organizer: 朝日カルチャーセンター藤沢
  • Invited
• [Presentation] 初期宇宙からの重力波とDECIGO (2020)
  • Author(s): 郡和範
  • Organizer: 第19回DECIGOワークショップ Online
  • Invited
• [Presentation] 原始ブラックホール (2020)
  • Author(s): 郡和範
  • Organizer: 素粒子現象論研究会 2020、大阪市大、大阪
  • Invited
• [Presentation] KAGRAと基礎物理 (2020)
  • Author(s): 郡和範
  • Organizer: KEK 研究推進会議 KAGRA, KEKつくば、つくば市
  • Invited
• [Presentation] MeV-scale reheating temperature and neutrino oscillation in the early Universe (2020)
  • Author(s): 郡和範
  • Organizer: 新学術領域「ニュートリノで拓く素粒子と宇宙」2020 Online
• [Presentation] Curvaton and the Moduli problem in supergravity (2020)
  • Author(s): 郡和範
  • Organizer: KEK CMBグループ年始発表会 Online
  • Invited
• [Presentation] Series At the cutting edge of research on black holes , ``The Nobel Prize in Physics 2020: 1/2 (2020)
  • Author(s): 郡和範
  • Organizer: 朝日カルチャーセンター藤沢
  • Invited
• [Presentation] NANOGrav12.5yr hints of Gravitational Waves and Solar-Mass Primordial Black Holes (2020)
  • Author(s): 郡和範
  • Organizer: 新学術 重力波創世記 The Forth Annual Area Symposium Online
  • Int'l Joint Research
• [Presentation] Series: At the cutting edge of research on black holes , ``The Nobel Prize in Physics 2020: 2/2 (2020)
  • Author(s): 郡和範
  • Organizer: 朝日カルチャーセンター藤沢
  • Invited
• [Presentation] What is the spacetime of the Universe? (2020)
  • Author(s): 郡和範
  • Organizer: 渋谷区ハチコウ大学
  • Invited
• [Book] 「ニュートリノと重力波」のことが一冊でまるごとわかる (2021)
  • Author(s): 郡 和範
  • Total Pages: 274
  • Publisher: ベレ出版
  • ISBN: 978-4860646493
• [Book] 宇宙物理学ハンドブック (2020)
  • Author(s): 高原文郎、家正則、小玉英雄、高橋忠幸 他
  • Total Pages: 912
  • Publisher: 朝倉書店
  • ISBN: 978-4254131277
• [Book] 相対論と宇宙の事典 (2020)
  • Author(s): 安東正樹、白水徹也、浅田秀樹、石橋明浩、小林努、真貝寿明、早田次郎、谷口敬介 他
  • Total Pages: 432
  • Publisher: 朝倉書店
  • ISBN: 978-4254131284
• [Remarks] KEK-Cosmo on "Dark Matter"
  • URL: https://conference-indico.kek.jp/event/117/timetable/#day-2020-10-13
• [Remarks] KEK-Cosmo on "Gravitational Wave"
  • URL: https://conference-indico.kek.jp/event/117/timetable/#day-2020-11-04
• [Funded Workshop] 3rd KEK-PH + KEK-Cosmo Joint Lectures and Workshop on "Dark Matter" (2020)
• [Funded Workshop] 4th KEK-PH + KEK-Cosmo Joint Lectures and Workshop on "Gravitational Wave" (2020)