双奇核^(176)Ir转动带的旋称反转(英文)

Signature Inversion Phenomena in the Rotational Bands of Odd-Odd ^(176)Ir

利用1 4 9Sm( 31 P ,4nγ)反应 ,通过γ射线的激发函数测量、X γ和γ γ符合测量研究了双奇核1 76Ir的高自旋态 .首次建立了双奇核1 76Ir由 4个转动带构成的能级纲图 .依据从实验数据中提取出的带内B(M1 ) B(E2 )值与理论计算值的比较 ,以及相邻双奇核的带结构特征 ,给出了转动带的准粒子组态 .基于本实验建立起的带间跃迁和在I=1 8处观测到的旋称交叉 ,指出1 76Ir核基于πh9 2 νi1 3 2 和πi1 3 2 νi1 3 2 组态的两个转动带在低自旋时出现旋称反转现象 .

High spin states in 176 Ir have been investigated via the 149 Sm( 31 P,4nγ) 176 Ir reaction through excitation functions, X γ and γ γ coincidence measurements. Four rotational bands have been identified for the first time and their configurations are suggested on the basis of the existing knowledge of band structures in odd odd nuclei as well as the measured in band B (M1)/ B (E2) ratios. Among the four bands observed,the π h 9/2 ν i 13/2 and π i 13/2 ν i 13/2 bands exhibit an anomalous signature splitting. The signature inversion point is observed in the former at I c=18  which is consistent with expectations;this signature inversion spin in the π i 13/2 ν i 13/2 band may be larger than 25  .