We seek to obtain a usable form of the nuclear energy density functional that is rooted in the modern theory of nuclear forces . We thus consider a functional obtained from the density matrix expansion of local nuclear potentials from chiral effective field theory . We propose a parametrization of this functional carefully calibrated and validated on selected ground-state properties that is suitable for large-scale calculations of nuclear properties. The first component of this functional is a non-local functional of the density and corresponds to the direct part (Hartree term) of the expectation value of local chiral potentials on a Slater determinant. A second component is a local functional of the density and is obtained by applying the density matrix expansion to the exchange part (Fock term) of the expectation value of the local chiral potential. We apply the UNEDF2 optimization protocol to determine the coupling constants of this energy functional. We obtain a set of microscopically-constrained functionals for local chiral potentials from leading-order up to next-to-next-to-leading order with and without three-body forces and contributions from $Δ$ excitations. These functionals are validated on the calculation of nuclear and neutron matter, nuclear mass tables, single-particle shell structure in closed-shell nuclei and the fission barrier of $^{240}$ Pu. Quantitatively, they perform noticeable better than the more phenomenological Skyrme functionals. The inclusion of higher-order terms in the chiral perturbation expansion seems to produce a systematic improvement in predicting nuclear binding energies. This result is especially promising since all the fits have been performed at the single reference level of the energy density functional approach, where important collective correlations such as center-of-mass correction have not been taken into account yet.
英文摘要:
We seek to obtain a usable form of the nuclear energy density functional that is rooted in the modern theory of nuclear forces. We thus consider a functional obtained from the density matrix expansion of local nuclear potentials from chiral effective field theory. We propose a parametrization of this functional carefully calibrated and validated on selected ground-state properties that is suitable for large-scale calculations of nuclear properties. The first component of this functional is a non-local functional of the density and corresponds to the direct part (Hartree term) of the expectation value of local chiral potentials on a Slater determinant. A second component is a local functional of the density and is obtained by applying the density matrix expansion to the exchange part (Fock term) of the expectation value of the local chiral potential. We apply the UNEDF2 optimization protocol to determine the coupling constants of this energy functional. We obtain a set of microscopically-constrained functionals for local chiral potentials from leading-order up to next-to-next-to-leading order with and without three-body forces and contributions from $Δ$ excitations. These functionals are validated on the calculation of nuclear and neutron matter, nuclear mass tables, single-particle shell structure in closed-shell nuclei and the fission barrier of $^{240}$Pu. Quantitatively, they perform noticeable better than the more phenomenological Skyrme functionals. The inclusion of higher-order terms in the chiral perturbation expansion seems to produce a systematic improvement in predicting nuclear binding energies. This result is especially promising since all the fits have been performed at the single reference level of the energy density functional approach, where important collective correlations such as center-of-mass correction have not been taken into account yet.
Microscopically-based energy density functionals for nuclei using the density matrix expansion: Implementation and pre-optimization
In a recent series of papers, Gebremariam, Bogner, and Duguet derived a microscopically based nuclear energy density functional by applying the Density Matrix Expansion (DME) to the Hartree-Fock energy obtained from chiral effective field theory (EFT) two- and three-nucleon interactions. Due to the structure of the chiral interactions, each coupling in the DME functional is given as the sum of a coupling constant arising from zero-range contact interactions and a coupling function of the density arising from the finite-range pion exchanges. Since the contact contributions have essentially the …
Odd-even mass differences of well and rigidly deformed nuclei in the rare earth region: A test of a newly proposed fit of average pairing matrix elements
Hartree-Fock emulators for nuclei: Application to charge radii of $^{48,52}$Ca
Technische Universität Darmstadt(达姆施塔特工业大学);ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH(极端物质研究所 (EMMI),GSI 重离子研究中心有限公司);Max-Planck-Institut für Kernphysik(马克斯·普朗克核物理研究所)
Predictions of charge density distributions for nuclei with $Z \geq 8$
College of Physics, Jilin University(吉林大学物理学院);Department of Physics, Graduate School of Science, The University of Tokyo(东京大学研究生院物理系);Quark Nuclear Science Institute, The University of Tokyo(东京大学夸克核科学研究所);RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program(理化学研究所跨学科理论与数学科学项目)
Frontiers Science Center for Rare isotope, Lanzhou University(兰州大学稀有同位素前沿科学中心);School of Nuclear Science and Technology, Lanzhou University(兰州大学核科学与技术学院);State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University(北京大学物理学院核物理与技术国家重点实验室);Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-sen University(中山大学中法核工程与技术学院)