Unification of Low Energy Standard Model Effective Field Theories

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K03846
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 15010:Theoretical studies related to particle-, nuclear-, cosmic ray and astro-physics
• Research Institution: Nagoya University
• Principal Investigator: Tanabashi Masaharu 名古屋大学, 理学研究科, 教授 (00270398)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 素粒子質量の起源 / 電弱対称性の破れ / 有効理論 / 標準模型を超える物理 / 素粒子現象論

Outline of Final Research Achievements

We formulate a generalization of Higgs effective field theory (HEFT) including arbitrary number of extra neutral and charged Higgs bosons (generalized HEFT, GHEFT). It is shown that the scalar boson scattering amplitudes are described in terms of the Riemann curvature tensor (geometry) of the scalar manifold and the covariant derivatives of the potential. The coefficients of the one-loop divergent terms can also be written in terms of the Killing vectors (symmetry) and the Riemann curvature tensor (geometry).

We also formulate an extension of Higgs effective field theory which contains arbitrary number of scalar and fermion fields with arbitrary electric and chromoelectric charges. The chiral order counting rule is arranged consistently with the loop expansion. The parametrization redundancy in the effective Lagrangian is resolved by describing the on-shell scattering amplitudes only with the covariant quantities in the scalar/fermion field space.

Free Research Field

素粒子理論

Academic Significance and Societal Importance of the Research Achievements

その起源が量子色力学の次元変性であることが知られているQCDスケールと異なり、電弱対称性の破れのスケール、つまり素粒子質量の起源はいまだ明らかになっていない。これまで多くの素粒子標準理論を超える物理の可能性が検討されてきたが、本研究は、これらの素粒子標準理論を超える物理を個々に調べるのではなく、統一的な有効理論を構築するアプローチをとった。 具体的には、 ヒッグス有効理論を拡張し、任意個数、任意電荷、任意色荷をもつスピン0、スピン1、スピン1/2粒子を含む有効理論での素粒子散乱振幅や輻射補正の一般的表式を与え、コライダー物理やフレーバー物理で行われている新粒子探索に対して統一的な理解を与えた。