Extremely asymmetric shears band in Sm143
Extremely asymmetric shears band in
Sm143
复制标题
Sm143 中极其不对称的剪切带
作者：
S. Rajbanshi;R. Raut;H. Pai;Sajad Ali;A. Goswami;S. Bhattacharyya;G. Mukherjee;R. Bhowmik;S. Muralithar;R. Singh;G. Gangopadhyay;M. Raju;P. Singh
用印度国家γ阵列（INGA）作为探测系统，对重离子引起的聚变-蒸发反应产生的~（143）Sm核中的偶极序列进行了观测和研究。该序列已被建立为一个磁旋转（MR）带主要从使用多普勒频移衰减法（DSAM）的频带成员的寿命测量。在主轴曲柄（SPAC）模型的Shears机制框架内，根据理论计算，将一种具有高度非对称角动量叶片的九个准粒子的组态分配给剪切带。这是迄今为止最大数量的准粒子沿着与MR带相关的最高不对称性。此外，正如SPAC计算所得出的那样，核心转动对剪切带角动量的贡献是相当大的，至少在相邻的核中，比任何其他类似的序列都要大。因此，这条带可以被认为是一个独特的剪切机制的现象，在准粒子激发的极限，表现在MR带状现象，演变成集体。
A dipole sequence has been observed and investigated in the 143 Sm nucleus populated through the heavy-ion induced fusion-evaporation reaction and studied using the Indian National Gamma Array (INGA) as the detection system. The sequence has been established as a Magnetic Rotation (MR) band primarily from lifetime measurements of the band members using the Doppler Shift Attenuation Method (DSAM). A configuration based on nine quasiparticles, with highly asymmetric angular momentum blades, has been assigned to the shears band in the light of the theoretical calculations within the framework of Shears mechanism with the Principal Axis Cranking (SPAC) model. This is hitherto the maximum number of quasiparticles along with the highest asymmetricity associated with a MR band. Further, as it has followed from the SPAC calculations, the contribution of the core rotation to the angular momentum of this shears band is substantial and greater than in any other similar sequence, at least in the neighbouring nuclei. This band can thus be perceived as a unique phenomenon of shears mechanism in operation at the limits of quasiparticle excitations, as manifested in MR band-like phenomena, evolving into collectivity.