AI 中文总结
研究48个N>20的偶偶稳定核的0基态正宇称→2第一激发态正宇称跃迁的Mn/Mp，发现部分形变稀土核、中等质量振动核的比值与液滴模型等预期不符，提出壳模型研究或可解释该现象。
AI 中文摘要
我们对48个N>20的偶偶稳定核中0基态正宇称→2第一激发态正宇称跃迁的中子与质子跃迁矩阵元比值Mn/Mp进行了研究，这些核的电磁矩阵元由Pritychenko等人汇编，且具备高质量的非弹性质子散射数据。多个形变稀土核的(Mn/Mp)/(N/Z)值显著低于1.0，这与简单的液滴模型图像不符，但可通过以下示意图解释：质子跃迁矩阵元Mp在质子满壳层中间（Z=66）达到最大值，中子跃迁矩阵元Mn在中子满壳层中间（N=104）达到最大值。多个中等质量振动核的Mn/Mp值显著低于N/Z，这与这类核中Mn/Mp=N/Z的预期不符。对这些观测结果开展壳模型研究或能为该现象提供见解。
英文摘要
We examined the ratios of neutron and proton transition matrix elements, $M_n/M_p$, for the $0_{gs}^+ \rightarrow 2_1^+$ transitions in 48 even-even stable nuclei with $N>20$ for which electromagnetic matrix elements were compiled by Pritychenko \textit{et al.} and for which high-quality inelastic proton scattering data were available. Several deformed rare earth nuclei have $(M_n/M_p)/(N/Z)$ values significantly below 1.0, which is not consistent with a simple liquid drop picture. However, this phenomenon can be explained using a schematic picture in which $M_p$ reaches a maximum at proton mid-shell ($Z=66$) and $M_n$ reaches its maximum at neutron mid-shell ($N=104$). Several mid-mass vibrational nuclei have $M_n/M_p$ values significantly below $N/Z$, which is not consistent with the expectation that $M_n/M_p = N/Z$ in such nuclei. A shell model investigation of these observations might yield insights about this behavior.
Comments15 pages, 2 figures
