AI 中文总结
该研究基于投影壳模型计算奇质量核的核能级密度，对比相邻偶偶核与奇A核的NLD，揭示奇质量核NLD的统计行为更早显现等特性，可绘制能量、自旋、宇称依赖的NLD。
AI 中文摘要
在最近的一篇文章[Phys. Rev. C 108, 034309 (2023)]中，我们提出了一种用于计算变形偶偶核中核能级密度（NLD）的投影壳模型方法。本文呈现了对奇质量核中NLD的后续研究，以及我们计算的相邻偶偶核与奇A核系统中NLD的对比分析。由于奇质量核系统中有一个核子被阻断参与对形成，导致对力减弱（由更小的BCS对能隙评估），我们发现奇质量核（包括偶奇和奇偶）与其紧邻的偶偶核之间的NLD存在显著差异。总体而言，在低能下偶偶核NLD中突出的、由结构主导的变化，在奇质量核系统中被大幅抑制。具体而言，从低至2 MeV的激发能开始，奇质量核中奇宇称和偶宇称能级的计算密度呈现均等划分，表明其统计行为的实现更快。两种宇称的核能级自旋分布都比偶偶核系统更早呈现规则的高斯形状。此外，我们的壳模型结果具有一个良好特性：每个计算的能级都是角动量的本征态，这使我们能够提取Ericson自旋分布公式中与能量相关的色散σ的值，并绘制出依赖于能量、自旋和宇称的能级密度ρ(E, I, π)。
英文摘要
In a recent article [Phys. Rev. C 108, 034309 (2023)], we proposed a projected shell model method for the calculation of nuclear level density (NLD) in deformed even-even nuclei. The current article presents the subsequent study of NLDs in odd-mass nuclei as well as a comparative analysis between our calculated NLDs in adjacent even-even and odd-A systems. Since one nucleon in the odd-mass system remains blocked from participating in the pair formation, resulting in a weakened pairing (assessed by a smaller BCS pairing gap), pronounced differences between the NLDs in an odd-mass (both even-odd and odd-even) nucleus and its immediate even-even neighbour have been found. In general, the structure-dominated variations, which were found to be prominent in the even-even NLD at low energies, are greatly suppressed in the odd-mass systems. Specifically, from excitation energy as low as 2 MeV, the calculated densities of odd-parity and even-parity levels in odd-mass nuclei show an equal division signaling faster attainment of the statistical behavior. Nuclear level-spin distributions of both parities have been seen to adopt a regular Gaussian shape earlier than that found in the even-even system. Moreover, the pleasant property of our shell-model results, that each of our calculated levels is an eigenstate of angular momentum, allows us to extract the values of the energy-dependent dispersion $σ$ of Ericson's spin-distribution formula and plot $ρ(E, I, π)$, the energy-, spin-, and parity-dependent level density.
Journal refPhysical Review C 111, 034324 (2025)
DOI：10.1103/PhysRevC.111.034324
