ヒッグス粒子発見後の素粒子物理学の新展開～LHCによる真空と時空構造の解明～

• Project Area: New expansion of particle physics of post-Higgs era by LHC revealing the vacuum and space-time structure
• Project/Area Number: 16K21730
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Multi-year Fund
• Review Section: Science and Engineering
• Research Institution: The University of Tokyo
• Principal Investigator: 浅井 祥仁 東京大学, 大学院理学系研究科(理学部), 教授 (60282505)
• Project Period (FY): 2016-06-30 – 2021-03-31
• Project Status: Granted (Fiscal Year 2019)
• Budget Amount: ¥52,650,000 (Direct Cost: ¥40,500,000、Indirect Cost: ¥12,150,000); Fiscal Year 2020: ¥10,530,000 (Direct Cost: ¥8,100,000、Indirect Cost: ¥2,430,000); Fiscal Year 2019: ¥10,530,000 (Direct Cost: ¥8,100,000、Indirect Cost: ¥2,430,000); Fiscal Year 2018: ¥10,530,000 (Direct Cost: ¥8,100,000、Indirect Cost: ¥2,430,000); Fiscal Year 2017: ¥10,530,000 (Direct Cost: ¥8,100,000、Indirect Cost: ¥2,430,000); Fiscal Year 2016: ¥10,530,000 (Direct Cost: ¥8,100,000、Indirect Cost: ¥2,430,000)
• Keywords: 素粒子実験 / 素粒子論 / 加速器

Outline of Annual Research Achievements

LHCのエネルギーはH28年度に倍増され、約170b-1近いデータが蓄積された。これらの成果を、今後の領域活動に生かすべく、国際研究支援班はH31年度は2つの活動の柱を中心に研究を行った。1つ目は、若手の研究者が国外の研究機関に長期滞在し共同研究を進めることで、本領域の研究を深め、研究を発展させた。H31年度は、京都大学の隅田氏がイタリアに長期滞在し、次世代の高速エレクトロニクス開発を進め、次世代素粒子実験での実用化を目指す研究を行った。
2つ目は、領域総括班と共同で国際研究会を開催し、本領域の研究成果を広く国外に発信すると共に、領域外の関係研究者との意見交換を行うことにより、領域の研究を広げた。H31年度は、11月に「Dark Matter Searches in 2020s」、2月に「KEK PH2020」という2つの大規模な国際会議を開催した。特に、Dark Matter Searchesは、本領域のLHCでの成果と、地下での直接実験、宇宙線観測による間接実験の3極を結ぶ試みであり、領域の成果を発信し、新しい知見を取り入れ、活発な議論が行われた。
2つ目と並んで研究成果を海外との共同研究に広げるために、各計画研究と共同で、ミニ国際会議を多数開催してきた。

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

H30年度までに、合わせて170fb-1近いデータを収集し、これらのデータを用いた解析を進め、この成果を発表し、１）機械学習を用いて、ボトムクォークとヒッグス粒子の結合の強さを世界で初めて観測し、力を伝える素粒子ばかりでなく、物質を形作る素粒子の質量の起源も、同じヒッグス粒子であることを示した。２）ヒッグス粒子を詳細に調べることで、我々の真空が、一番安定な状態ではなく、少しエネルギーが高く不安定であることが判明した。（ある日、宇宙全体が相転移してこの宇宙が変わってしまう可能性は、極めて低いが、安定ではない）　このことは、標準理論は不完全なものであり、何かよりエネルギーの低い真空に対応する新現象があることが発見されたことになり、重要な成果である。
２月から、新型コロナウィルス感染症のために、研究者が往来しにくくなっている。これに伴い、数件の研究会、招聘、長期滞在がキャンセルになっている。H31年度は、研究自体のは大きな影響はでていないが、実施自体には影響が出始めている、

Strategy for Future Research Activity

今後も3つの柱を中心に研究の国際活動支援を行う。1つ目の若手研究者の海外研究機関への長期滞在は、R2年度は数名を予定し、領域関係者や関係研究に公募の呼びかけを行い、候補者の中から総括班会議で選ぶ。全データを用いた研究が進むので、国際共同研究が盛んになることが期待されている。また海外の研究者を招聘し、長期滞在して共同研究を行う活動も予定している。
国際会議の開催を通して、領域の成果を国内外に発信する。R2年度は本領域主催の大型国際会議の開催予定を予定し、中規模・小規模のworkshopを開催して、研究を進めていくが、新型コロナウィルス感染症のために、一部の大型国際会議を、翌年度に変更したり、ZOOMなどのオンラインを使う方法を検討している。

Research Products

• [Int'l Joint Research] INFN Roma-I/INFN Pisa/University of Florence(イタリア)
• [Int'l Joint Research] CERN(スイス)
• [Int'l Joint Research] SLAC/Boston University/University of Michigan(米国)
• [Int'l Joint Research] Max-Plank Institute(ドイツ)
• [Int'l Joint Research] Durham University/University of Cambridge(英国)
• [Int'l Joint Research]
• [Int'l Joint Research] INFN Roma-I/INFN Pisa/University of Florence(イタリア)
• [Int'l Joint Research] CERN(スイス)
• [Int'l Joint Research] SLAC/Boston University/University of Michigan(米国)
• [Int'l Joint Research] Max-Planck Institute(ドイツ)
• [Int'l Joint Research] Durham University/University of Cambridge(英国)
• [Int'l Joint Research]
• [Int'l Joint Research] INFN Roma-I/INFN-Pisa/University of Florence(イタリア)
• [Int'l Joint Research] CERN(スイス)
• [Int'l Joint Research] SLAC/Boston University/University of Michigan(アメリカ)
• [Int'l Joint Research] Max-Planck Institute(ドイツ)
• [Int'l Joint Research] Durham University/University of Cambridge(イギリス)
• [Int'l Joint Research]
• [Journal Article] Studying gaugino masses in supersymmetric model at future 100 TeV collider (2019)
  • Author(s): Asai Shoji、Chigusa So、Kaji Toshiaki、Moroi Takeo、Saito Masahiko、Sawada Ryu、Tanaka Junichi、Terashi Koji、Uno Kenta
  • Journal Title: JHEP05(2019)179 Volume: 2019 Pages: 179-179
  • DOI: 10.1007/jhep05(2019)179
  • Peer Reviewed / Open Access
• [Journal Article] Discovery reach for wino and higgsino dark matter with a disappearing track signature at a 100 TeV pp collider (2019)
  • Author(s): Saito Masahiko、Sawada Ryu、Terashi Koji、Asai Shoji
  • Journal Title: European Physical Journal C Volume: 79 Pages: 469-469
  • DOI: 10.1140/epjc/s10052-019-6974-2
  • Peer Reviewed / Open Access
• [Journal Article] Review of Particle Physics (2019)
  • Author(s): Tanabashi M.、Hagiwara K.、Hikasa K.、Nakamura K.、Murayama H.、et al.
  • Journal Title: Physical Review D Volume: 98 Pages: 030001-030001
  • DOI: 10.1103/physrevd.98.030001
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] FCC-hh: The Hadron Collider: Future Circular Collider Conceptual Design Report Volume 3 (2019)
  • Author(s): A. Abada, S. Asai, J. Tanaka et al
  • Journal Title: European Physical Journal: Special Topics Volume: 228 Pages: 755-1107
  • DOI: 10.1140/epjst/e2019-900087-0
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Search for long-lived, massive particles in events with displaced vertices and missing transverse momentum in sqrt(s) =13 TeV pp collisions with the ATLAS detector (2018)
  • Author(s): M. Aaboud, K. Hanagaki, J. Tojo, F. Ukegawa, et al. [ATLAS Collaboration]
  • Journal Title: Physical Review D Volume: 97 Pages: 052012-052012
  • DOI: 10.1103/physrevd.97.052012
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Evidence for the associated production of the Higgs boson and a top quark pair with the ATLAS detector (2018)
  • Author(s): ATLAS Collaboration
  • Journal Title: Physical Review D Volume: 97 Pages: 072003-072003
  • DOI: 10.1103/physrevd.97.072003
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Search for W W/W Z resonance production in lνqq final states in pp collisions at root(s)=13 TeV with the ATLAS detector (2018)
  • Author(s): The ATLAS collaboration (M. Aaboud, M. Ishino, H. Nanjo, T. Sumida, K. Yorita et al.)
  • Journal Title: Journal of High Energy Physics (JHEP) Volume: 3 Pages: 042-042
  • DOI: 10.1007/jhep03(2018)042
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Model independent evaluation of the Wilson coefficient of the Weinberg operator in QCD (2018)
  • Author(s): T. Abe, J. Hisano and R. Nagai
  • Journal Title: Journal of High Energy Physics Volume: 3 Pages: 175-175
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Search for new phenomena with large jet multiplicities and missing transverse momentum using large-radius jets and flavour-tagging at ATLAS in 13 TeV pp collisions (2017)
  • Author(s): T.Saito et al., ATLAS Collaboration
  • Journal Title: J. High Energ. Phys. Volume: 12 Pages: 1-50
  • DOI: 10.1007/jhep12(2017)034
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Evidence for the H→bbbar decay with the ATLAS detector (2017)
  • Author(s): Aaboud M. et. al. (The ATLAS collaboration)
  • Journal Title: JHEP Volume: 2017 Pages: 024-024
  • DOI: 10.1007/jhep12(2017)024
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Subnanosecond time-to-digital converter implemented in a Kintex-7 FPGA (2017)
  • Author(s): Sano Y.、Horii Y.、Ikeno M.、Sasaki O.、Tomoto M.、Uchida T.
  • Journal Title: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Volume: 874 Pages: 50-56
  • DOI: 10.1016/j.nima.2017.08.038
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Dark matter physics, flavor physics and LHC constraints in the dark matter model with a bottom partner (2017)
  • Author(s): T.Abe, J.Kawamura, S.Okawa, Y.Omura
  • Journal Title: JHEP Volume: - Pages: 042-042
  • DOI: 10.1007/jhep03(2017)058
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Presentation] 「素粒子物理実験」とAIの接点 (2019)
  • Author(s): 田中純一
  • Organizer: JSAI2019
  • Invited
• [Presentation] Search for additional neutral Higgs bosons in the MSSM (2018)
  • Author(s): J. Tanaka
  • Organizer: ICHEP2018
  • Int'l Joint Research
• [Presentation] Status and highlights from the ATLAS experiment (2018)
  • Author(s): K. Nagano
  • Organizer: LHCP2018
  • Int'l Joint Research / Invited
• [Presentation] Single Event Upsets in the ATLAS IBL Frontend ASICs (2018)
  • Author(s): Y. Takubo
  • Organizer: Pixel2018
  • Int'l Joint Research
• [Presentation] Study of efficiency and noise of fine pitch planar pixel detector for ATLAS ITk upgrade (2018)
  • Author(s): K. Nakamura
  • Organizer: Pixel2018
  • Int'l Joint Research
• [Presentation] Searches for new physics in final states with top quarks with ATLAS (2018)
  • Author(s): M. Aoki
  • Organizer: LHCP2018
  • Int'l Joint Research
• [Presentation] ATLAS Detector Performance in Run2 and Upgrade Plans (2017)
  • Author(s): Masaya Ishino (for ATLAS collaboration)
  • Organizer: High-Energy Physics International Conference in Quantum Chromodynamics
  • Int'l Joint Research
• [Presentation] Mono-jet searches (2017)
  • Author(s): Osamu Jinnouchi (for ATLAS and CMS collaborations)
  • Organizer: DM @ LHC 2017
  • Int'l Joint Research
• [Presentation] Baryon-number violating nucleon decay - Review from theoretical (2017)
  • Author(s): Junji Hisano
  • Organizer: NNN17
  • Int'l Joint Research
• [Presentation] Searches for Beyond SM Higgs bosons (2017)
  • Author(s): Soshi Tsuno
  • Organizer: The 28th International Symposium on Lepton Photon Interactions at High Energies
  • Int'l Joint Research
• [Presentation] The alignment limit in two Higgs doublet models (2017)
  • Author(s): Sabine Kraml
  • Organizer: HPNP2017
  • Place of Presentation: 富山大学（富山県富山市）
  • Int'l Joint Research / Invited
• [Presentation] Flavor physics induced by light Z′ from SO(10) GUT. (2016)
  • Author(s): Y. Omura
  • Organizer: B2Tips workshop
  • Place of Presentation: Munich (Germany)
  • Year and Date: 2016-11-15
  • Int'l Joint Research
• [Presentation] Exploring neutrino mass generation mechanisms via the lepton flavor violating decay of the Higgs boson (2016)
  • Author(s): H. Sugiyama
  • Organizer: DISCRETE2016
  • Place of Presentation: Warszawa (Poland)
  • Int'l Joint Research
• [Presentation] Neutrinos at LHC (2016)
  • Author(s): T. Sumida
  • Organizer: LHC Days 2016
  • Place of Presentation: Split (Croatia)
  • Int'l Joint Research / Invited
• [Funded Workshop] 新テラスケール研究会 (2019)
• [Funded Workshop] HNPN2019 (2019)
• [Funded Workshop] DIS2018 (2018)
• [Funded Workshop] ATLAS Overview Week (2018)
• [Funded Workshop] HC2018 (2018)
• [Funded Workshop] LAr Week March 2018 in Tokyo (2018)
• [Funded Workshop] ATLAS CERN-Tokyo 2017 Winter/Spring Workshop (2017)
  • Place of Presentation: 東京大学（東京都文京区）
  • Year and Date: 2017-03-23
• [Funded Workshop] Physics in LHC and the Early Universe (2017)
  • Place of Presentation: 東京大学（東京都文京区）
  • Year and Date: 2017-01-09