Exotic Deformations at High Spin in Unsteble Nuclei
Project/Area Number  08640368 
Research Category 
GrantinAid for Scientific Research (C)

Section  一般 
Research Field 
素粒子・核・宇宙線

Research Institution  KYOTO UNIVERSITY 
Principal Investigator 
MATSUYANAGI Kenich KYOTO UNIVERSITY,Department of Physics, Graduate School of Science, Associate Professor, 大学院・理学研究科, 助教授 (70025451)

Project Fiscal Year 
1996 – 1997

Project Status 
Completed(Fiscal Year 1997)

Budget Amount *help 
¥1,300,000 (Direct Cost : ¥1,300,000)
Fiscal Year 1997 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1996 : ¥700,000 (Direct Cost : ¥700,000)

Keywords  Superdeformation / HighSpinStates / Octupole Deformation / Exotic Deformation / Shell Structure / Unstable Nuclei / Cranking Model / Rotational Band / 超変形核 / 高スピン状態 / 8重極変形 / エキゾチック変形 / シェル構造 / 不安定核 / クランキング模型 / 回転バンド / 八重極変形 
Research Abstract 
1.To investigate possible occurrence of exotic deformations in protonrich N<similar or equal>Z unstable unclei in the A=3060 region, we have constructed a new powerful computer program for the Cranked SkyrmeHartreeFock calculations. The program is written in terms of the threedimensional coordinate mesh representation without imposing any spatial symmetry restriction and use the imaginary time propagation technique. As the first application of this computer program, we have investigated highspin states in ^<32>S and obtained the following theoretical predictions : 1)Appearance of an exotic rotational band possessing the Y_<31>type deformation, in the region of the yrast line with angular momentum I=612, which simulataneously breaks the spacereflection and axial symmetries. 2)The superdeformed rotational band appear in the yrast line above I<similar or equal>14 and it shows an interesting internal structure change above I<similar or equa 2.Classical periodic orbits responsible for emergence of the superdeformed shell structure for singleparticle motions in spheroidal cavities have been identified and their relative contributions to the shell structures evaluted. Both prolate and oblate superdeformations as well as prolate hyperdeformations have been investigated. Fourier transform of quantum spectra clearly show that threedimensional orbits born out of bifurcations of planar orbits in the equatorial plane become predominant at large prolate deformations while butterflyshaped planar orbits bifurcated from linear orbits along the minor axis are important at large oblate deformations. Good correspondence between constantaction lines for these periodic orbits and valley structure in the oscillating part of the smoothed level density confirms the above conclusion.

Report
(4results)
Research Output
(10results)