Explicit Energy Functional for Infinite Nuclear Matter with the Tensor Force

17th International Conference on Recent Progress in Many-Body Theories

Takano, M.^1,2 ; Kato, K.^2 ; Yamada, M.^1

Research Institute for Science and Engineering, Waseda University, Tokyo, Japan^1

Department of Physics and Applied Physics, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan^2

关键词: Finite temperatures;    Structure functions;    Tensor structure function;    Three-body clusters;    Three-body potential;    Two-body distribution function;    Variational functions;    Variational methods;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/529/1/012025/pdf
DOI  :  10.1088/1742-6596/529/1/012025

来源: IOP

【 摘 要 】

We have applied the variational method using explicit energy functionals (EEFs) to energy calculations of infinite nuclear matter. In EEFs, the energy per nucleon is explicitly expressed with spin-isospin-dependent two-body distribution functions, which are regarded as variational functions, and fully minimized energies are conveniently calculated with the EEF. A remarkable feature of this approach is that EEFs guarantee non-negativeness of structure functions. In this study, we extend the EEF variational method so as to consider state- independent three-body forces for neutron matter at finite temperatures following the procedure proposed by Schmidt and Pandharipande. For neutron matter, the free energies obtained with the Argonne v4' two-body potential and the repulsive part of the Urbana IX (UIX) three- body potential are quite reasonable. Furthermore, we improve the EEF of nuclear matter using the two-body central and tensor forces by considering the main three-body cluster terms and guaranteeing non-negativeness of tensor structure functions. In addition, healing distances are introduced for two-body distribution functions so that Mayer's condition is satisfied. The obtained energies per neutron of neutron matter with the Argonne v6' two-body potential and the repulsive part of the UIX potential are in good agreement with those obtained by auxiliary field diffusion Monte Carlo calculations.