矩方法在TALYS中的实现：$^{56,57}$Fe$(n,γ)$可观测量对壳模型核能级密度的敏感性
Implementation of the Moments Method in TALYS: Sensitivity of $^{56,57}$Fe$(n,γ)$ observables to shell model nuclear level densities
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中文总结 AI 辅助
本研究将矩方法（MM）集成到TALYS程序，探究$^{56,57}$Fe中子俘获反应对核能级密度的敏感性，发现可观测量对γ射线强度函数的敏感性远高于MM能级密度，且MM结果与评估数据吻合良好。
中文摘要 AI 辅助
矩方法（MM）是一种基于组态相互作用壳模型哈密顿量的统计谱学框架，可在无需对多体哈密顿量进行完全对角化的情况下实现核能级密度的壳模型描述，该方法被集成到TALYS反应程序中，以研究$^{56}$Fe$(n,γ)^{57}$Fe和$^{57}$Fe$(n,γ)^{58}$Fe反应的豪泽-费施巴赫计算对核能级密度输入的敏感性。将在pf壳中计算的、与自旋和宇称相关的MM能级密度与TALYS程序对接，并与该程序中可用的唯象和微观能级密度模型进行比较。为构建适用于TALYS的输入，采用背移费米气体延拓结合实验约束的相反宇称态处方，将MM能级密度扩展到更高激发能。通过改变控制能级密度统计重建的单个参数，估算MM计算的敏感性范围。将中子俘获截面、麦克斯韦平均截面和反应率与评估的ENDF/B-VIII.0数据及推荐的KADoNiS、JINA-CEE值进行比较，以评估核能级密度和γ射线强度函数输入的相对重要性。计算表明，相较于此处考虑的MM能级密度变化，可观测量对γ射线强度函数的选择敏感得多，而基于MM的结果与评估的截面及推荐的天体物理反应率仍吻合良好。
英文摘要
The Moments Method (MM), a statistical spectroscopy framework built upon configuration interaction shell model Hamiltonians that enables shell model descriptions of nuclear level densities without requiring full diagonalization of the many body Hamiltonian, is implemented in the TALYS reaction code to investigate the sensitivity of Hauser-Feshbach calculations for the $^{56}$Fe$(n,γ)^{57}$Fe and $^{57}$Fe$(n,γ)^{58}$Fe reactions to the nuclear level density input. Spin- and parity-dependent MM level densities calculated in the pf shell are interfaced with TALYS and compared with the phenomenological and microscopic level density models available in the code. To construct TALYS-ready inputs, the MM level densities are extended to higher excitation energies using a back shifted Fermi gas continuation together with an experimentally constrained prescription for opposite-parity states. A sensitivity band for the MM calculations is estimated by varying a single parameter governing the statistical reconstruction of the level density. Neutron capture cross sections, Maxwellian averaged cross sections, and reaction rates are compared with evaluated ENDF/B-VIII.0 data and recommended KADoNiS and JINA-CEE values to assess the relative importance of the nuclear level density and $γ$-ray strength function inputs. The calculations show that the observables are considerably more sensitive to the choice of $γ$-ray strength function than to the MM level density variation considered here, while the MM-based results remain in good agreement with evaluated cross sections and recommended astrophysical reaction rates.
