The Lippmann-Schwinger equation for the nucleon-nucleon $t$-matrix as well as the corresponding Bethe-Goldstone equation to determine the Brueckner reaction matrix in nuclear matter are reformulated in terms of the resolvents for the total two-nucleon Hamiltonians defined in free space and in medium correspondingly. This allows to find solutions at many energies simultaneously by using the respective Hamiltonian matrix diagonalization in the stationary wave packet basis. Among other important advantages, this approach simplifies greatly the whole computation procedures both for coupled-channel $t$-matrix and the Brueckner reaction matrix. Therefore this principally novel scheme is expected to be especially useful for self-consistent nuclear matter calculations because it allows to accelerate in a high degree single-particle potential iterations. Furthermore the method provides direct access to the properties of possible two-nucleon bound states in the nuclear medium. The comparison between reaction matrices found via the numerical solution of the Bethe-Goldstone integral equation and the straightforward Hamiltonian diagonalization shows a high accuracy of the method suggested. The proposed fully discrete approach opens a new way to an accurate treatment of two- and three-particle correlations in nuclear matter on the basis of three-particle Bethe-Faddeev equation by an effective Hamiltonian diagonalization procedure.
Antisymmetrized molecular dynamics of wave packets with stochastic incorporation of Vlasov equation
在量子系统波包的反对称分子动力学(AMD)基础上,采用Vlasov方程计算波包的扩散和形变,构造了一种新的量子系统模型(AMD-V),对单体分布没有任何限制.换句话说,在分子动力学中的随机分支过程的制定,使平均的单体分布的瞬时时间演化本质上是等价的Vlasov方程的解。此外,与通常的分子动力学一样,AMD-V保持了多体关联,能够自然地描述反应多个通道之间的涨落。结果表明,新引入的AMD-V过程对35 MeV/nucleon的40 Ca +40 Ca重离子碰撞,特别是碎裂机制有很大影响,能很好地再现碎裂数据。讨论了AMD、AMD-V和其它核动力学微观模型框架之间的相互关系。
Landau theory of nuclear level density and its application in description of nuclear level density in the region of discrete and s-wave neutron resonance energies
Effects of nuclear correlations on the $^{16}$O$(e,e'pN)$ reactions to discrete final states
计算了$^{14}$ N和$^{14}$ C核的基态和第一激发态的$^{14}$ $(e,e'pN)$截面.核碎裂的影响已获得在一个自洽的方法,并占在确定的两个核子去除幅度。希尔伯特空间被划分,以便以单独的方式计算长程和短程效应的贡献。两个质子和质子-中子发射截面都是在相同的反应机制模型和原子核结构的贡献下计算的,目的是更好地比较两个物理过程之间的差异。的$^{16}$ O $(e,e'pp)$反应被发现是敏感的短程相关性,与以前的结果一致。从$^{16}$ O $(e,e'pn)$到$1^+$最终态的截面由$Δ$电流和张量关联决定。对于这两种反应,集体(长程)效应与短程和张量相关性之间的相互作用起着重要作用。这表明,$(e,e'pN)$反应对最终状态的选择性也可用于探测超出短程效应的相关性。