Study on physical laws behind Higgs boson looking forward ILC experiment

2021 Fiscal Year Final Research Report

• Project/Area Number: 17K05413
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Shinshu University
• Principal Investigator: Kawamura Yoshiharu 信州大学, 学術研究院理学系, 教授 (10224859)
• Project Period (FY): 2017-04-01 – 2022-03-31
• Keywords: ヒッグス粒子 / 質量階層性 / フレーバー混合 / フレーバー対称性 / 余剰次元 / オービフォールド

Outline of Final Research Achievements

We have derived the standard model from Pati-Salam type model on a five-dimensional space-time, using an orbifold breaking and Coleman-Weinberg mechanism. We have derived enormous numbers of models with three families of the standard model matter multiplets from a massless Dirac fermion in a vectorlike representation of SU(N) gauge theory on a six-dimensional space-time. We have found that there is a possibility that the hierarchical flavor structure of quarks and charged leptons originates from non-canonical types of fermion kinetic terms in the presence of flavor-symmetric Yukawa interactions and a flavor symmetry can be hidden in the form of non-unitary bases in the standard model. We have clarified how a mechanism works to realize the hierarchy without severe fine tuning and a smallness of fermion masses is understood naturally.

Free Research Field

素粒子物理学

Academic Significance and Societal Importance of the Research Achievements

素粒子の標準模型の構成要素であるヒッグス粒子や3世代の物質粒子（クォーク，レプトン）がより基本的な理論から導出され，また，物質粒子の構造（質量階層性，フレーバー混合）も理解される可能性が見出されたことにより，我々を含むこの宇宙の万物の存在が偶然ではなく必然として捉えることが可能になる。必然性を支持する存在理由が明らかになると，基本的な物理法則が我々の行う様々な知的活動における哲学的な基盤になる可能性が生まれる。