Study of Lambda's g-factor in a nucleus via hypernuclear gamma-ray spectroscopy

2014 Fiscal Year Final Research Report

• Project/Area Number: 23244043
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Tohoku University
• Principal Investigator: TAMURA Hirokazu 東北大学, 理学研究科, 教授 (10192642)
• Co-Investigator(Renkei-kenkyūsha): KOIKE Takeshi 東北大学, 理学研究科, 准教授 (70396422) ; MIWA Koji 東北大学, 理学研究科, 助教 (50443982) ; UKAI Mifuyu 東北大学, 理学研究科, 助教 (30420053) ; HIYAMA Emiko 理化学研究研, 仁科加速器研究センター, 准主任研究員 (10311359)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Keywords: 実験核物理 / ハイパー核 / ストレンジネス / ガンマ線分光 / 磁気モーメント / Λ粒子 / 媒質効果 / J-PARC

Outline of Final Research Achievements

By measuring the g-factor of a Λ particle in a nucleus via B(M1) values of spin-flip γ-transitions of hypernuclei using hypernuclear γ-ray spectroscopy, we study possible nuclear medium effects of baryons. For this purpose, we have prepared for the J-PARC E13 experiment; we developed, manufactured, installed, and tested a germanium detector array, Hypernball-J, and various detectors for the K1.8/SKS magnetic spectrometers. A new high-rate readout method of Ge detctors has been also developed. The whole apparatus has been tested with an actual K- beam at K1.8 beam line and found to have good performance. In addition, new data for the (K-,π-) reaction cross sections were also obtained.
Unfortunately, due to an accident at the J-PARC facility in May of 2013, our beam time postponed for almost 2 years and we were not able to take physics data by the end of FY2014. However, we will be able to obtain physics results for 19ΛF hypernucleus immediately after beam recovery in April 2015.

Free Research Field

実験核物理