Modern energy density functional and the current status of the equation of state of nuclear matter

2012 ◽  
Author(s):  
S. Shlomo
Keyword(s):  
Equation Of State ◽  
Energy Density ◽  
Nuclear Matter ◽  
Density Functional ◽  
Current Status ◽  
Energy Density Functional

scholarly journals Nuclear Equation of State in the Relativistic Point-Coupling Model Constrained by Excitations in Finite Nuclei

Universe ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 71
Author(s):  
Esra Yüksel ◽  
Tomohiro Oishi ◽  
Nils Paar
Keyword(s):  
Experimental Data ◽  
Equation Of State ◽  
Energy Density ◽  
Symmetry Energy ◽  
Ground State ◽  
Density Functional ◽  
Dipole Polarizability ◽  
Energy Density Functional ◽  
Nuclear Equation Of State ◽  
Ground State Properties

Nuclear equation of state is often described in the framework of energy density functional. However, the isovector channel in most functionals has been poorly constrained, mainly due to rather limited available experimental data to probe it. Only recently, the relativistic nuclear energy density functional with an effective point-coupling interaction was constrained by supplementing the ground-state properties of nuclei with the experimental data on dipole polarizability and isoscalar monopole resonance energy in 208Pb, resulting in DD-PCX parameterization. In this work, we pursue a complementary approach by introducing a family of 8 relativistic point-coupling functionals that reproduce the same nuclear ground-state properties, including binding energies and charge radii, but in addition have a constrained value of symmetry energy at saturation density in the range J = 29, 30, …, 36 MeV. In the next step, this family of functionals is employed in studies of excitation properties such as dipole polarizability and magnetic dipole transitions, and the respective experimental data are used to validate the optimal choice of functional as well as to assess reliable values of the symmetry energy and slope of the symmetry energy at saturation.

scholarly journals KIDS Energy Density Functional and Mass–Radius Relation of Neutron Stars

2019 ◽  
Vol 26 ◽  
pp. 112
Author(s):  
G. Ahn ◽  
P. Papakonstantinou
Keyword(s):  
Equation Of State ◽  
Energy Density ◽  
Neutron Stars ◽  
Symmetry Energy ◽  
Density Functional ◽  
Nuclear Symmetry Energy ◽  
Unified Framework ◽  
Energy Density Functional ◽  
Nuclear Equation Of State ◽  
Derivatives Of

Many efforts are made to determine the nuclear equation of state which governs the properties and evolution of neutron stars. Especially important is to constrain the parameters of the nuclear symmetry energy. In those efforts, nuclear energy density functional (EDF) theory has been a very useful tool, as it provides a unified framework for the description both of nuclei, which can be studied on Earth, and of infinite matter and its nuclear equation of state, which is a necessary input in the modelling of neutron stars. In the present study, a new nuclear EDF, the KIDS functional, is explored with a focus on the nuclear symmetry energy. The form of the functional allows us to vary at will the poorly constrained high-order derivatives of the symmetry energy and examine how the maximum possible mass of a neutron star is affected. Some tentative constraints on the skewness are presented, which will help guide further refinements. It is noteworthy that the pressure of neutron-rich matter is found strongly affected by skewness variations, both at low and high densities.

scholarly journals LOCAL ENERGY-DENSITY FUNCTIONAL APPROACH TO MANY-BODY NUCLEAR SYSTEMS WITH S-WAVE PAIRING

2001 ◽  
Vol 15 (10n11) ◽  
pp. 1684-1702 ◽  
Author(s):  
S. A. FAYANS ◽  
D. ZAWISCHA
Keyword(s):  
Energy Density ◽  
Nuclear Matter ◽  
Density Gradient ◽  
Density Functional ◽  
Effective Density ◽  
Local Energy ◽  
Energy Density Functional ◽  
Density Dependent ◽  
Nuclear Systems ◽  
Local Energy Density

The ground-state properties of superfluid nuclear systems with 1S0 pairing are studied within a local energy-density functional (LEDF) approach. A new form of the LEDF is proposed with a volume part which fits the Friedman-Pandharipande and Wiringa-Fiks-Fabrocini equation of state at low and moderate densities and allows an extrapolation to higher densities which preserves causality. For inhomogeneous systems, a surface term is added, with two free parameters, which has a fractional form like a Padé approximant containing the square of the density gradient in both the numerator and denominator. In addition to the direct and exchange Coulomb interaction energy, an effective density-dependent Coulomb-nuclear correlation term is included with one more free parameter. A three-parameter fit to the masses and radii of about 100 spherical nuclei has shown that the latter term gives a contribution of the same order of magnitude as the Nolen-Schiffer anomaly in the Coulomb displacement energy. The root-mean-square deviations from experimental masses and radii with the proposed LEDF come out about a factor of two smaller than those obtained with the conventional functionals based on the Skyrme or finite-range Gogny force, or on relativistic mean-field theory. The generalized variational principle is formulated leading to the self-consistent Gor'kov equations which are sovled exactly, with physical boundary conditions both for the bound and scattering states. The method is used to calculate the differential observables such as odd-even mass differences and staggering in charge radii. With a zero-range density-dependent cutoff pairing interaction incorporating a density-gradient term, the evolution of these observables is reproduced reasonably well, including the kinks at magic neutron numbers and the sizes of the associated staggering. An extrapolation from the pairing properties of finite nuclei to pairing in infinite nuclear matter is discussed. A "reference" value of the pairing gap ΔF≈ 3.3 MeV is found for subsaturated nuclear matter at about 0.65 of the equilibrium density. With the formulated LEDF approach, we study also the dilute limit in both the weak and strong coupling regimes. Within the sum rules approach it is shown that the density-dependent pairing may also induce sizeable staggering and kinks in the evolution of the mean energies of multipole excitations.

scholarly journals Octupole correlations in light actinides from the interacting boson model based on the Gogny energy density functional

2020 ◽  
Vol 102 (6) ◽  
Author(s):  
K. Nomura ◽  
R. Rodríguez-Guzmán ◽  
Y. M. Humadi ◽  
L. M. Robledo ◽  
J. E. García-Ramos
Keyword(s):  
Energy Density ◽  
Density Functional ◽  
Interacting Boson Model ◽  
Energy Density Functional ◽  
Model Based ◽  
Boson Model
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