Excitations of Isovector Monopole Resonance in Nuclei

Research Project

Project/Area Number	07640426
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	素粒子・核・宇宙線
Research Institution	Kobe Tokiwa Jr. College
Principal Investigator	TANAKA Masayoshi Kobe Tokiwa Jr. College, Dept. of Clinical Technology, Professor, 衛生技術科, 教授 (70071397)
Co-Investigator(Kenkyū-buntansha)	NAKAYAMA Shintaro Tokushima University, Facul. of Arts and Sciences, Professor, 総合科学部, 教授 (70116846)
Project Period (FY)	1995 – 1996
Project Status	Completed (Fiscal Year 1996)
Budget Amount *help	¥2,300,000 (Direct Cost: ¥2,300,000) Fiscal Year 1996: ¥300,000 (Direct Cost: ¥300,000) Fiscal Year 1995: ¥2,000,000 (Direct Cost: ¥2,000,000)
Keywords	Isovector Monopole / Giant Dipole Resonance / Spin Dipole Resonance / One particle one hole / Statistical model / Neutron decay / GSO counter / Grand Raiden / 1粒子1孔 / 集団励起モード / アイソスカラー / アイソベクター / 巨大共鳴 / 準弾性散乱 / 圧縮運動 / 星の進化
Research Abstract	We searched for the Isovector giant resonance by means of a tripple coincidence method among decay neutrons, 430 keV gamma-rays from the first excited state of ^7Be and scattered ^7Be following the (^7Li, ^7Be) reaction on ^<12>C using a 65 AMev ^7Li beam from a Ring cyclotron at RCNP.Osaka University. For detection of 7Be scattered at 0 degrees the magnetic spectrograph, "Grand-Raiden" was used. For detection of 430 keV gamma-rays and decay neutrons a GS0-counter array composed of 22 counter segments and liquid neutron counter arrays composed of 48 segments were used. It was found that we could succeeded in observing neutron decays from the isovector non spin-flip (DELTAS=0) states separately from the isovector spin-flip (DELTAS=1) states for the first time. This will hopefully provide a delightfull direction toward the discovery of the Isovector Giant Monopole Resonance.