Study of three-nucleon forces via deuteron-proton scattering using polarized proton target

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K22345
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0203:Particle-, nuclear-, astro-physics, and related fields
• Research Institution: Tohoku University
• Principal Investigator: Watanabe Atomu 東北大学, 理学研究科, 特任助教 (10882011)
• Project Period (FY): 2020-09-11 – 2022-03-31
• Keywords: 三体力 / 核力 / 偏極陽子 / 動的核偏極

Outline of Final Research Achievements

With the aim of the investigation for the three-nucleon forces, which play an important role in nuclear properties, we plan to perform the measurement of spin-correlation coefficients for deuteron-proton scattering. In this work, we developed a polarized proton target for this measurement. As a result, we succeeded to generate the polarization with a dynamic nuclear polarization method and achieved a high polarization of about 40%. On the other hand, there were some issues such as the difficulty of long-term operation with liquid nitrogen cooling and the depolarization effect due to beam irradiation at the accelerator facility. It was found that improvements such as the development of a polarized proton target that can be operated at room temperature are necessary.

Free Research Field

原子核物理

Academic Significance and Societal Importance of the Research Achievements

原子核物理では、現在三体核力を系統的に記述する核力の記述が進みつつあり、その構築に当たっては三核子系散乱におけるスピン相関係数の高精度データが強く要請されている。本研究で開発した偏極陽子標的はこの測定に必要不可欠であり、また他の原子核物理実験にも広く応用可能である。本研究で見られた課題を克服することで、三体核力を含む高度な核力の構築や、原子核物理学の発展に資することができる。