Rotational bands in odd-A Re and Au nuclei
M. OshimaY. TohM. KoizumiA. OsaT. HayakawaY. HatsukawaT. ShizumaF. R. XuM. Sugawara
Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195, JapanDepartment of Technical Physics, Peking University, Beijing 100871, ChinaChiba Institute of Technology, Narashino, Chiba 275-0023, Japan
摘要：<正> High-spin states in 169Re were studied and resulted in the identification of a strongly coupled band based on the 9/2- Nilsson state and a decouplcd band built on the 1/2-(h9/2) intruder proton orbit. The cranked shell model calculations present configuration-dependent deformations that can explain the different band crossing frequencies. The 9/2- band in 169Re shows the largest signature splitting at low spin among the known odd mass Re isotopes. After the alignment of a pair of i13/2 neutrons, the phase of the splitting is inverted with a significantly reduced amplitude. For the 9/2- bands in light odd-A Re isotopes, the signature splitting of the Routhians and its relation with the signature dependence of M1 transition matrix elements are investigated in connection with the deviation of nuclear shape from axial symmetry, suggesting an appreciable negative γdeformation for the very neutron-deficient odd-A Re isotopes. A rotational band built on the 1/2(i13/2) Nilsson orbital has been established for 179Au. Properties of the 1/2(i13/2) bands in the odd-A Au nuclei are discussed with an emphasis on the evolution of band head energy and deformation while changing neutron number.