变形晕核的转动及形状退耦合效应

Rotating deformed halo nuclei and shape decoupling effects

晕核是由核芯和弱束缚且轨道角动量较低的价核子组成的体系.晕现象以及与之相关的奇特核结构是当前核物理研究的重要前沿领域.近年来,实验已证实了变形晕核的存在,但人们对变形晕核的激发模式仍然知之甚少.为了探索变形晕核的转动以及在低激发转动态中核芯和价核子的行为,作者在包含连续谱贡献的协变密度泛函理论基础上进行角动量投影,在狄拉克-伍兹-萨克森基中求解平均场方程并展开投影激发态波函数,恰当描述弱束缚原子核中核子波函数的渐近行为.他们利用该理论研究了变形晕核镁-42和镁-44的转动激发模式.研究结果表明在低激发转动态中依然存在变形晕现象以及核芯与晕的形状退耦合现象.

To explore the rotational excitation of deformed halo nuclei,the angular momentum projection(AMP)has been implemented in the deformed relativistic Hartree-Bogoliubov theory in continuum(DRHBc),in which both the mean field and collective wave functions are expanded in terms of Dirac WoodsSaxon basis.The DRHBc+AMP approach self-consistently describes the coupling between single particle bound states and the continuum not only in the ground state but also in rotational states.The rotational modes of deformed halos in ^(42,44)Mg are investigated by studying properties of rotational states such as the excitation energy,configuration,and density distribution.Our study demonstrates that the deformed halo structure persists from the ground state in the intrinsic frame to collective states.Especially,the typical behavior of shape decoupling effects in rotating deformed halo nuclei is revealed.