Spectroscopy of eta'-mesic nuclei as an approach to study of QCD vacuum

2023 Fiscal Year Final Research Report

• Project/Area Number: 18H01242
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 15020:Experimental studies related to particle-, nuclear-, cosmic ray and astro-physics
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Itahashi Kenta 国立研究開発法人理化学研究所, 開拓研究本部, 専任研究員 (30322093)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: η′ / 量子異常 / 軸性U(1)対称性

Outline of Final Research Achievements

The η′ nuclear spectroscopy experiment (Experimental Task No. S490) was carried out at the German Heavy Ion Research Institute (GSI) with a beam time of about 5 days. A beam of about 100 million 2.5 GeV protons per second was irradiated onto a carbon target. Deuterons emitted forward by the 12C(p,d) reaction were measured in the forward spectrometer in coincidence with the particles emitted around the target measured by a large solid angle detector WASA. The analysis is in progress, and the status of the analysis is being reported in the form of proceedings and presentations at research conferences. As soon as the analysis is completed, a paper will be written, submitted and published.

Free Research Field

ハドロン実験

Academic Significance and Societal Importance of the Research Achievements

擬スカラーη′中間子を原子核という超高密度物質中で分光することで、物質質量の起源に関する知見を得ることをめざす。η′中間子の大質量は素粒子物理における重要な問題、η問題として捉えられており、その解決が待たれている。本研究では、陽子ビームを使ったη′中間子原子核の生成・分光実験を実施し、当初の予定通りの統計量のデータを得る事に成功した。2024/5現在解析を行っており、終了次第論文執筆、投稿を行う。