nucl-th digest · Jan 31, 2022

New many-body method using cluster expansion diagrams with tensor-optimized antisymmetrized molecular dynamics

We propose a new many-body method based on the correlation functions, in which the multiple products of the correlation functions are expanded into the many-body diagrams using the cluster expansion method and every diagram is independently optimized in the total-energy variation. We apply this idea to the tensor-optimized antisymmetrized molecular dynamics (TOAMD) using the bare nucleon-nucleon interaction and show the results of the

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-shell nuclei within the triple products of the correlation functions of tensor and central-types. We evaluate the effect of the independent optimization of the many-body diagrams on the solutions. It is found that the triple products provides the sizable effect in the present scheme, which results in the good reproduction of the total energy and the Hamiltonian components of nuclei with respect to the few-body calculations.

Comments:: 12 pages, 13 figures
Subjects:: Nuclear Theory (nucl-th)
arXiv:: 2201.11877 [pdf]

PRC(2022)·4 citations

[Submitted on 28 Jan 2022]

Unified nuclear matter EOSs constrained by the in-medium balance in density-dependent covariant density functionals

Cheng-Jun Xia · Bao Yuan Sun · Toshiki Maruyama · Wen-Hui Long · Ang Li

Considering the effects of charge screening, we propose a new numerical recipe within the framework of Thomas-Fermi approximation, where the properties of nuclear matter throughout a vast density range can be obtained self-consistently. Assuming spherical and cylindrical approximations for the Wigner-Seitz cell, typical nuclear matter structures (droplet, rod, slab, tube, bubble, and uniform) are observed. We then investigate the EOSs and microscopic structures of nuclear matter with both fixed proton fractions and $β$ -equilibration, where two covariant density functionals DD-LZ1 and DD-ME2 are adopted. Despite the smaller slope $L$ of symmetry energy obtained with the functional DD-LZ1, the curvature parameter $K_{sym}$ is much larger than that of DD-ME2, which is attributed to the peculiar density-dependent behavior of meson-nucleon couplings guided by the restoration of pseudo-spin symmetry around the Fermi levels in finite nuclei. Consequently, different mass-radius relations of neutron stars are predicted by the two functionals. Different microscopic structures of nonuniform nuclear matter are obtained as well, which are expected to affect various physical processes in neutron star properties and evolutions.

Subjects:: Nuclear Theory (nucl-th)
arXiv:: 2201.12053 [pdf]

PRC(2022)·25 citations

Monday·January 31, 2022

New many-body method using cluster expansion diagrams with tensor-optimized antisymmetrized molecular dynamics

Unified nuclear matter EOSs constrained by the in-medium balance in density-dependent covariant density functionals

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