Self-consistent calculation of nuclear photoabsorption cross sections: Finite amplitude method with Skyrme functionals in the three-dimensional real space
Self-consistent calculation of nuclear photoabsorption cross sections: Finite amplitude method with Skyrme functionals in the three-dimensional real space
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DOI：
10.1103/physrevc.80.044301
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发表时间：
2009-06
影响因子：
3.1
通讯作者：
T. Inakura;T. Nakatsukasa;K. Yabana
中科院分区：
文献类型：
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作者：
T. Inakura;T. Nakatsukasa;K. Yabana
我们最近提出的有限振幅法（FAM）[T. Nakatsukasa、T. Inakura 和 K. Yabana，物理学家。 Rev. C 76, 024318 (2007)] 显着简化了随机相位近似 (RPA) 的完全自洽计算。本文提出了一种适合系统研究的 FAM 计算方案，并展示了其在现实 Skyrme 能量泛函中的性能。我们采用混合表示，其中前向和后向 RPA 幅度由空穴轨道索引和三维实空间的空间网格点索引来表示。我们使用迭代方法解决具有稀疏非厄米矩阵的线性代数问题。我们展示了选定球形核和变形核的偶极子响应结果。计算出的巨偶极子共振峰值能量与重核实验非常吻合。然而，对于轻核来说，它们被系统性地低估了。我们还讨论了完全自洽 RPA 计算中巨偶极子共振的宽度。
The finite amplitude method (FAM), which we have recently proposed [T. Nakatsukasa, T. Inakura, and K. Yabana, Phys. Rev. C 76, 024318 (2007)], significantly simplifies the fully self-consistent calculation of the random-phase approximation (RPA). This article presents a computational scheme of FAM suitable for systematic investigation and shows its performance for realistic Skyrme energy functionals. We adopt the mixed representation in which the forward and backward RPA amplitudes are represented by index of hole orbitals and of the spatial grid points for the three-dimensional real space. We solve a linear algebraic problem with a sparse non-Hermitian matrix, using an iterative method. We show results of the dipole response for selected spherical and deformed nuclei. The calculated peak energies of the giant dipole resonance well agree with experiments for heavy nuclei. However, they are systematically underestimated for light nuclei. We also discuss the width of the giant dipole resonance in the fully self-consistent RPA calculation.