A≈160质量区奇A核的形状演化效应

摘要

【目的】研究A≈160质量区奇A核高激发态的形状演化性质。【方法】基于来自 National Nuclear Data Center的实验数据，采用修正后的 E-Gamma Over Spin(E-GOS)曲线方法首次系统性地探讨了A≈160质量区奇A核处于高激发态的激发特性。【结果】提取得到的E-GOS曲线表明该质量区原子核的形变与未配对中子的组态密切相关，当核外价中子占据高j 轨道时，随着角动量的增加将对核芯产生强大的形状驱动效应。此外，根据E-GOS曲线的变化特征，发现在 Yb同位素的高自旋能级结构中存在明显的形状演化现象，即随着角动量的增加原子核的激发机制从振动逐渐演化为转动。【结论】在A≈160质量区奇A核中系统性地存在形状演化现象。%Objective]The paper aims at studying the structure evolution of the odd-A nuclei withA≈ 160 at high spin states.[Methods]Based on the experimental data from Nuclear Data Center National,the E-Gamma Over Spin(E-GOS)curves after correction were used firstly to investigate the structure evolution in the odd-Anuclei withA≈160 as a function of spin.[Re-sults]The nuclear shape is closely related to the neutron configuration,and the polarizing effect would begin to influence the core as valence nucleons start to fill high j neutron orbitals with increasing spin.Furthermore,it is founded that there is a clear structure evolution at high spin states of Yb isotopes based on the E-GOS characteristics.Namely,the Yb isotopes display a vi-brational character at low spins,whereas at higher spins they have a rotational pattern.[Conclu-sion]The phenomena of structure evolution were found in the odd-Anuclei withA≈ 160.