KOSHIGIRI Kunio Osaka Kyoiku University, 教育学部, 教授 (90153527)
SAGAWA Hiroyuki Aizu University, 理学部, 教授 (50178589)
FUKUDA Mitsunori Graduate School of Science, 大学院・理学研究科, 助教授 (50218939)
MATSUTA Kensaku Graduate School of Science, 大学院・理学研究科, 助教授 (50181722)
NOJIRI Yoichi Faculty of Engineering, Kochi Institute of Technology, 工学部, 教授 (90028233)
|Budget Amount *help
¥39,300,000 (Direct Cost : ¥39,300,000)
Fiscal Year 2000 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1999 : ¥4,600,000 (Direct Cost : ¥4,600,000)
Fiscal Year 1998 : ¥15,800,000 (Direct Cost : ¥15,800,000)
Fiscal Year 1997 : ¥17,900,000 (Direct Cost : ¥17,900,000)
We established the technique of the production of unstable nuclei, developed the spin control technique, determined the magnetic moments and the quadrupole moments of unstable nuclei, the interaction cross-sections, and finally determined the induced tensor term and the axial charge in the weak nucleon currents in the mirror beta decays. From these results,of the present stydy can be summarized as follows.
1 Nuclear spin polarizations of ^<8, 12>B, ^9C, ^<12, 16>N, ^<13, 19>O, ^<20, 21>F, ^<23>Mg, ^<27>Si, ^<35>Ar and ^<39>Ca produced through the projectile fragmentation process in hegh energy heavy ion collisions have been studied systematically. These studies made clear the polarization mechanism in heavy ion collisions and helped us to establish the polarized radioactive nuclear beam techniques.
2 We have determined the electric quadrupole moments of ^<12, 16>N, ^<13, 19>O, ^<21>F, ^<27>Si, ^<39>Ca and ^<41>Sc, and got information on the nucleon density distributions in these nuclei.
The electric field gradients (EFG) necessary for the studies have been given through electron band structure calculations in the framework of the KKR method. EFGs in the TiO_2crystal have been determined experimentally from the FT-NMR of the nuclei such as ^<17>O in the enriched Ti^<17>O_2.
3 Abnormally large spin expectation value in ^9C has been found, from the precise measurement of the magnetic moments of the extremely proton-rich nuclei ^9C and ^<13>O. This may suggest the signigicant renormalization of the g-factors in the nucleus, which is connected with the quark confinement mechanism.
4 Interaction cross-sections and the fragment momentum distributions of ^8B, ^<12>N, ^9C, ^<13>O and ^<17>Ne have been precisely measured. From these experimental data, nucleon density distributions in these nuclei were determined.
5 A new technique of spin control has been developed, and the nuclear alignment terms have been precisely measured for mass A = 12 mirror beta decays )^<12>B and ^<12>N). From the measurement, precise upper limit of the G-parity irregular induced tensor term was determined. The same data revealed the abnormally large axial charge in the weak nucleon currents, which is the reliable evidence of the renormalization of the nucleon mass (quenching of the nucleon mass) in the nucleus.
5 新しいスピンコントロール法を開発。核整列相関項の精密測定を行った。質量数12体系(^<12>B,^<12>N)ベータ崩壊におけるG-Parity異常誘導テンソル項の精密上限値を決定。また、巨大なアキシャルチャージを観測し、核子質量が核内で軽くなる再規格化を証明した。 Less