论文标题
从球形到变形的新近同位素的跨界的水平密度的强大增强
Strong enhancement of level densities in the crossover from spherical to deformed neodymium isotopes
论文作者
论文摘要
在核物理学中，了解从球形到良好的核的跨界核中水平密度的演变一直是一个长期存在的问题。我们测量了表现出如此跨界的一系列新近同位素$^{142,144-151} $ nd的核水平密度。这些结果代表了迄今为止，对于中子壳裂片和中壳之间的同位素链的核水平密度最完整的数据集。我们观察到沿链的水平密度的强劲提高，总体上增加了$ \ \ \ \ \ \ 170 $，激发能量为7.5 meV，质量为150左右。壳模型Monte Carlo（SMMC）计算出的水平密度与这些实验结果非常吻合。根据我们的实验和理论发现，我们根据固有的单粒子水平密度和集体增强的水平密度的观察到的质量依赖性提供了解释。
Understanding the evolution of level densities in the crossover from spherical to well-deformed nuclei has been a long-standing problem in nuclear physics. We measure nuclear level densities for a chain of neodymium isotopes $^{142,144-151}$Nd which exhibit such a crossover. These results represent to date the most complete data set of nuclear level densities for an isotopic chain between neutron shell-closure and towards mid-shell. We observe a strong increase of the level densities along the chain with an overall increase by a factor of $\approx 170$ at an excitation energy of 7.5 MeV and saturation around mass 150. Level densities calculated by the shell model Monte Carlo (SMMC) are in excellent agreement with these experimental results. Based on our experimental and theoretical findings, we offer an explanation of the observed mass dependence of the level densities in terms of the intrinsic single-particle level density and the collective enhancement.
