Self-consistent description of nuclear compressional modes
Self-consistent description of nuclear compressional modes
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DOI：
10.1103/physrevc.64.024307
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发表时间：
2001-03
影响因子：
3.1
通讯作者：
J. Piekarewicz
中科院分区：
文献类型：
--
作者：
J. Piekarewicz
在具有标量自相互作用的 Walecka 模型的三种不同参数化的相对论随机相位近似中，计算各种闭壳核的等标量单极子和偶极子压缩模式。特别强调的是自洽性的作用，它本身几乎不需要其他任何东西，就能保证寄生等标量偶极子强度与物理响应的解耦以及矢量电流的守恒。引入了一种强大的新关系来量化各种基态形状因子对矢量电流的破坏。对于等标量偶极子模式，可以清楚地识别出两个不同的区域：（i）对核的大小敏感并随模型的可压缩性缩放的高能分量，以及（ii）对核可压缩性不敏感的低能分量。通过使用压缩模量为 K=224MeV 的“软”参数化，可以获得两种压缩模式的相当好的描述。
Isoscalar monopole and dipole compressional modes are computed for a variety of closed-shell nuclei in a relativistic random-phase approximation to three different parametrizations of the Walecka model with scalar self-interactions. Particular emphasis is placed on the role of self-consistency which by itself, and with little else, guarantees the decoupling of the spurious isoscalar-dipole strength from the physical response and the conservation of the vector current. A powerful new relation is introduced to quantify the violation of the vector current in terms of various ground-state form factors. For the isoscalar-dipole mode two distinct regions are clearly identified: (i) a high-energy component that is sensitive to the size of the nucleus and scales with the compressibility of the model and (ii) a low-energy component that is insensitivity to the nuclear compressibility. A fairly good description of both compressional modes is obtained by using a ''soft'' parametrization having a compression modulus of K=224MeV.