^(129)Ce高自旋态的形状变化  

Shape Change of ^(129)Ce at High Spin States

作　　者：李广生[1] 戴征宇[1] 刘祥安[1] 张兰宽[1] 温书贤[1] 吴晓光[1] 袁观俊[1] 彭朝华[1] 翁培焜 李生岗[1] 杨春祥[1] 

机构地区：[1]中国原子能科学研究院,北京102413

出　　处：《高能物理与核物理》2001年第10期984-988,共5页High Energy Physics and Nuclear Physics

基　　金：国家自然科学基金(19975070)资助

摘　　要：　通过１１６Ｓｎ（１６Ｏ，３ｎ）１２９　Ｃｅ反应，利用多普勒移动衰减法测量了１２９Ｃｅ高自旋态的寿命．得到的跃迁四极矩表明１２９Ｃｅ的集体性相对于核芯１２８Ｃｅ减弱．这个因增加一个ｈ１１／２中子而引起集体性的降低可以解释为由于形状驱动效应产生三轴形变所造成的．正、负宇称带的跃迁四极矩与角动量的关系呈现相似的变化趋势，推测一对ｈ１１／２准质子可能对核芯性质起主要作用．High spin states of 129 Ce were populated through the reaction 116Sn(16O, 3n)129 Ce at a beam energy of 73 MeV. Lifetimes of the excited states were measured using the Doppler shift atten- uation method. The transition quadrupole moments Qt were deduced from lifetime data. The results indicate that collectivity of 129 Ce is reduced with respect to the even-even core 128 Ce. This reduction in collectivity caused by the addition of a h11/2 neutron can be interpreted as due to triaxial deforma- tion induced by shape driving effect. Although the Qt values of the negaive-parity band are some- what smaller than the ones of the positive-parity band, they exhibit a considerably sindlar behavior with increasing angular momentum. It would appear that the two h11/2 quasiprotons possibly have a dominant innuence on property of the core.

关 键 词：高自旋态 寿命测量 跃迁四极矩 ^129Ce 形状变化 集体性 角动量 核芯性质 

分 类 号：O571[理学—粒子物理与原子核物理]