Predictions to cosmology from gauge-Higgs unification and its extension to Planck scale physics

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K05420
• 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: Osaka City University
• Principal Investigator: Maru Nobuhito 大阪市立大学, 大学院理学研究科, 准教授 (40448163)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 高次元理論 / ゲージ・ヒッグス統一模型 / 暗黒物質 / バリオン数生成 / 電弱対称性の破れ

Outline of Final Research Achievements

We have studied the origin of dark matter, baryon asymmetry in the universe and the origin of the electroweak scale of unsolved problems in the Standard Model of particle physics from the viewpoint of gauge-Higgs unification model as one of the extension of the Standard Model.
On the dark matter, we have shown that Majorana fermion with a half of Higgs mass and the first Kaluza-Klein mode of the gauge field with same quantum number as Higgs field could be a dark matter. On baryogenesis, a possibility of electroweak baryogenesis has been analyzed. As a result, it was turned out that the temperature where baryon is generated is lower comparing to the weak scale, which implies a requirement for corrections of our model. In models of magnetic flux compactification, the electroweak scale can be derived even if the new physics scale is Planck scale. We have succeeded in reproducing fermion mass hierarchy in grand gauge-Higgs unification.

Free Research Field

素粒子論

Academic Significance and Societal Importance of the Research Achievements

素粒子物理、宇宙物理の謎である暗黒物質の起源について、素粒子に質量を与えるヒッグス場と電弱力を伝えるゲージ場を高次元時空で統一する模型の枠組みで、候補の１つを示せたことは意義があり、暗黒物質探索実験において発見される可能性を残した。標準模型を超える新物理の兆候がない現状に鑑み、新物理スケールがプランクスケールのような高いスケールの場合でも、余剰空間に磁場が入る場合は、電弱対称性のスケールが自然に導出できる可能性があり、新物理の新たなアプローチを提供するインパクトが期待される。