Study of right-handed neutrino masses using gravitational waves

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K03860
• 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: Hokkaido University
• Principal Investigator: Seto Osamu 北海道大学, 理学研究院, 准教授 (40547741)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 右巻きニュートリノ

Outline of Final Research Achievements

We considered a promising particle model. We identified the conditions under which a strong first-order phase transition can be realized, and based on the effective potential that also takes into account the radiative correction by the Yukawa coupling constant that generates right-handed neutrino masses. We found that the effect of Yukawa coupling, which produces right-handed neutrino masses, are implemented in the spectrum.
As related cosmological subjects, we also studied the matter-antimatter asymmetric generation and dark matter in the universe. We proposed an elementary particle model that explains the matter-antimatter asymmetry of the universe using right-handed neutrinos with masses of several hundred GeV, and derived constraints on dark matter candidates.

Free Research Field

宇宙論

Academic Significance and Societal Importance of the Research Achievements

本研究は、ニュートリノの質量の起源を探る研究の一環として加速器では発見しにくい重い右巻きニュートリノを質量起源と相互作用を宇宙論的考察と重力波を使って探ろう、というものである。素粒子の質量起源の問題だけに留まらず、宇宙の物質生成の機構にも関連ししており、世界の物質の起源の解明が進むという点でその社会的意義は大きい。