scholarly journals Relativistic density functional for nuclear matter

2019 ◽  
Vol 204 ◽  
pp. 05001
Author(s):  
Stefan Gmuca ◽  
Kristian Petrík ◽  
Jozef Leja
Keyword(s):  
Energy Density ◽  
Nuclear Matter ◽  
Density Functional ◽  
Mean Field ◽  
Dense Matter ◽  
Coupling Constants ◽  
Effective Coupling ◽  
Hartree Fock ◽  
Relativistic Mean Field ◽  
Rmf Model

In the present work, we have mapped the exchange Fock contributions from the Dirac–Hartree–Fock (DHF) approach for nuclear matter onto the direct Hartree terms. This results in the relativistic mean field (RMF) model with the density dependent couplings. The density dependence of the effective coupling constants thus reflects the exchange correlations. The exchange part of an energy density of the linear DHF model in dense matter is evaluated in a parameter-free closed form and, after the rearrangement of the terms, expressed as density functional.

A RELATIVISTIC MEAN FIELD THEORY FOR NUCLEAR MATTER AT T≠0

2004 ◽  
Vol 13 (07) ◽  
pp. 1177-1181
Author(s):  
ALEXANDRE MESQUITA ◽  
MOISÉS RAZEIRA ◽  
CÉSAR A. Z. VASCONCELLOS ◽  
MANFRED DILLIG ◽  
BARDO E. J. BODMANN
Keyword(s):  
Nuclear Matter ◽  
Mean Field Theory ◽  
Mean Field ◽  
Dense Matter ◽  
Baryon Number ◽  
Coupling Constants ◽  
Model Parameters ◽  
Static Properties ◽  
Relativistic Mean Field ◽  
Protoneutron Stars

We study effects of temperature in hadron dense matter within a generalized relativistic mean field approach based on the naturalness of the various coupling constants of the theory, The Lagrangian density of our formulation contains the fundamental baryon octet, nonlinear self-couplings of the σ and δ meson fields coupled to the baryons and to the ω and ρ meson fields. By adjusting the model parameters, after inclusion in a consistent way of chemical equilibrium, baryon number and electric charge conservation, our model describes static bulk properties of ordinary nuclear matter and neutron stars. In the framework of the Sommerfeld approximation, we extend our approach to the T≠0 domain. The Sommerfeld approximation allows a drastic simplification of computational work while improving the capability of the theoretical analysis of the role of temperature on static properties of protoneutron stars. We perform the calculations by using our nonlinear model, which we extend by considering trapped neutrinos introduced into the formalism by fixing the lepton fraction. Integrating the Tolman–Oppenheimer–Volkoff equations we have obtained standard plots for the mass and radius of protoneutron stars as a function of the central density and temperature. Our predictions include the determination of an absolute value for the protoneutron star limiting mass at low and intermediate temperature regimes.

THE INNER CRUST OF NEUTRON STARS IN RELATIVISTIC MEAN FIELD APPROACH

2008 ◽  
Vol 17 (09) ◽  
pp. 1765-1773 ◽  
Author(s):  
JIGUANG CAO ◽  
ZHONGYU MA ◽  
NGUYEN VAN GIAI
Keyword(s):  
Boundary Conditions ◽  
Neutron Stars ◽  
Mean Field ◽  
Bcs Theory ◽  
Neutron Density ◽  
Field Approach ◽  
Hartree Fock ◽  
Relativistic Mean Field ◽  
Density Distributions ◽  
Rmf Model

The microscopic properties and superfluidity of the inner crust in neutron stars are investigated in the framework of the relativistic mean field(RMF) model and BCS theory. The Wigner-Seitz(W-S) cell of inner crust is composed of neutron-rich nuclei immersed in a sea of dilute, homogeneous neutron gas. The pairing properties of nucleons in the W-S cells are treated in BCS theory with Gogny interaction. In this work, we emphasize on the choice of the boundary conditions in the RMF approach and superfluidity of the inner crust. Three kinds of boundary conditions are suggested. The properties of the W-S cells with the three kinds of boundary conditions are investigated. The neutron density distributions in the RMF and Hartree-Fock-Bogoliubov(HFB) models are compared.

DELTA MATTER FORMATION IN DENSE ASYMMETRIC NUCLEAR MEDIUM

2000 ◽  
Vol 15 (24) ◽  
pp. 1529-1537 ◽  
Author(s):  
J. C. T. DE OLIVEIRA ◽  
M. KYOTOKU ◽  
M. CHIAPPARINI ◽  
H. RODRIGUES ◽  
S. B. DUARTE
Keyword(s):  
Nuclear Matter ◽  
Mean Field Theory ◽  
Mean Field ◽  
Symmetric Nuclear Matter ◽  
Coupling Constants ◽  
Nuclear Medium ◽  
Delta Resonance ◽  
Relativistic Mean Field ◽  
Meson Coupling ◽  
Resonance Coupling

In the context of a relativistic mean field theory the delta-resonance matter formation in a highly compressed nuclear medium is investigated. For a given set of nucleon–meson coupling constants, the delta-resonance formation is studied by changing the delta-meson coupling constants. The effect on the equation of state and on the delta-resonance population with respect to changes in the delta-resonance coupling constants values is discussed for very asymmetric and quasi-symmetric nuclear matter, as an extension of works restricted to the symmetric nuclear matter treatment.5,6

scholarly journals Clusters as surrogate for explicit short-range correlations in relativistic mean-field models

2020 ◽  
Vol 229 (22-23) ◽  
pp. 3433-3444
Author(s):  
Stefan Typel
Keyword(s):  
Nuclear Matter ◽  
Density Functional ◽  
Degrees Of Freedom ◽  
Present Model ◽  
Mean Field ◽  
Theoretical Models ◽  
Density Functionals ◽  
Many Body ◽  
Relativistic Mean Field ◽  
Short Range Correlations

AbstractThe formation of clusters at sub-saturation densities in nuclear matter can be seen as a result of many-body correlations. Various theoretical models have been developed to take this effect into account, mostly on a phenomenological level using energy density functionals. These models are constructed in such a way that clusters appear solely in dilute matter and dissolve when the density approaches the nuclear saturation density. At higher densities only nucleons survive as quasi-particles and no explicit correlations between the constituents of nuclear matter are considered. The possible description of correlations with cluster degrees of freedom at supra-saturation densities is explored using the example of a quasi-deuteron in a generalized relativistic density functional. The required change in the density dependence of the cluster mass shift, responsible for describing the cluster dissolution in the present model, is derived for nuclear matter at zero temperature.

EFFECTS OF THE ω MESON SELF COUPLING ON THE THERMAL PROPERTIES OF ASYMMETRIC NUCLEAR MATTER

2009 ◽  
Vol 24 (11n13) ◽  
pp. 1067-1070
Author(s):  
S. WIBOWO ◽  
A. SULAKSONO
Keyword(s):  
Phase Transition ◽  
Thermal Properties ◽  
Nuclear Matter ◽  
Gas Phase ◽  
Mean Field ◽  
Binodal Curve ◽  
Asymmetric Nuclear Matter ◽  
Relativistic Mean Field ◽  
Chemical Instabilities ◽  
Rmf Model

Effects of the ω meson self coupling (OMSC) on the thermal properties of asymmetric nuclear matter (ANM) are studied within the framework of relativistic mean field (RMF) model that includes contributions of all possible mixed interactions among meson fields involved up to quartic order. In particular, we study the mechanical and chemical instabilities (spinodal), as well as the liquid-gas phase transition (binodal) at finite temperature. It is found that the onset of spinodal instabilities and the binodal curve are only marginally affected by variation of the OMSC parameter, whereas the binodal curve shows a strong correlation to the symmetry energy. Comparison with other ERMF parameter sets is also performed.

scholarly journals The properties of the massive neutron star PSR J0348+0432

2015 ◽  
Vol 24 (08) ◽  
pp. 1550058 ◽  
Author(s):  
Xian-Feng Zhao
Keyword(s):  
Neutron Star ◽  
Energy Density ◽  
Mean Field ◽  
Coupling Constants ◽  
Gravitational Redshift ◽  
Central Pressure ◽  
Relativistic Mean Field ◽  
Massive Neutron Star ◽  
Central Energy ◽  
Well Depth

The properties of the massive neutron star PSR J0348+0432 is calculated in the framework of the relativistic mean field (RMF) theory by choosing the suitable hyperon coupling constants. It is found that the central energy density ϵc and the central pressure pc of the massive neutron star PSR J0348+0432 respectively are 1.5 times larger and 3.6 times larger than those of the canonical mass neutron star. It is also found that in the neutron star PSR J0348+0432 there are five kinds of baryons appearing: n, p, Λ, Ξ- and Ξ0 but in the canonical mass neutron star there are only three kinds of particles appearing: n, p and Λ. In our models, the positive well depth [Formula: see text] will restrict the production of the hyperons Σ-, Σ0 and Σ+ and therefore either in the neutron star PSR J0348+0432 or in the canonical mass neutron star the hyperons Σ-, Σ0 and Σ+ all do not appear. In addition, our results also show that the radius R of the massive neutron star PSR J0348+0432 is less than that of the canonical mass neutron star while the gravitational redshift of the former is larger than that of the latter.

A FINITE TEMPERATURE RELATIVISTIC NUCLEAR MODEL FOR NEUTRON STARS IN A SLOW ROTATIONAL SCENARIO

2007 ◽  
Vol 16 (02n03) ◽  
pp. 341-345 ◽  
Author(s):  
ALEXANDRE MESQUITA ◽  
MOISES RAZEIRA ◽  
CÉSAR A. Z. VASCONCELLOS ◽  
BARDO E. J. BODMANN
Keyword(s):  
Neutron Stars ◽  
Finite Temperature ◽  
Mean Field ◽  
Dense Matter ◽  
Coupling Constants ◽  
Nuclear Model ◽  
Density Profiles ◽  
Stellar Objects ◽  
Relativistic Mean Field ◽  
Inertial Moment

We study the effects of temperature in hadron dense matter within a generalized relativistic mean field approach based on the naturalness of the coupling constants of the theory. The Lagrangian density of our formulation contains nonlinear self-couplings of the σ meson field coupled to baryons and to the ω and ϱ meson fields. Moreover, we use the Sommerfeld and Hartle approximations to extend our approach to the finite temperature domain and slow rotational scenario. Both Sommerfeld and Hartle approximation allows a drastic simplification of computational work while improving the capability of theoretical analysis of the role of temperature and rotation on properties of protoneutron stars. Our predictions indicate that in the slow rotating regimen, neutron stars density profiles as well as the maximum mass and the inertial moment of these stellar objects are well approximated by the zero temperature approximation.

SATURATION PROPERTIES OF NUCLEAR MATTER IN A RELATIVISTIC MEAN FIELD MODEL CONSTRAINED BY THE QUARK DYNAMICS

2007 ◽  
Vol 16 (07n08) ◽  
pp. 2400-2406
Author(s):  
R. HUGUET ◽  
J. C. CAILLON ◽  
J. LABARSOUQUE
Keyword(s):  
Nuclear Matter ◽  
Field Model ◽  
Mean Field ◽  
Coupling Constants ◽  
Meson Mass ◽  
Mean Field Model ◽  
Relativistic Mean Field ◽  
Saturation Properties ◽  
Omega Meson ◽  
Hadron Masses

We have built an effective Walecka-type hadronic Lagrangian in which the hadron masses and the density dependence of the coupling constants are deduced from the quark dynamics using a Nambu–Jona-Lasinio model. In order to stabilize nuclear matter an eight-quark term has been included. The parameters of this Nambu–Jona-Lasinio model have been determined using the meson properties in the vacuum but also in the medium through the omega meson mass in nuclei measured by the TAPS collaboration. Realistic properties of nuclear matter have been obtained.

scholarly journals Chirally Improved Quark Pauli Blocking in Nuclear Matter and Applications to Quark Deconfinement in Neutron Stars

Particles ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 477-499 ◽  
Author(s):  
David Blaschke ◽  
Hovik Grigorian ◽  
Gerd Röpke
Keyword(s):  
Nuclear Matter ◽  
Equations Of State ◽  
Compact Star ◽  
Mean Field ◽  
High Mass ◽  
Pauli Blocking ◽  
Density Dependent ◽  
Relativistic Mean Field ◽  
Njl Model ◽  
Rmf Model

The relativistic mean field (RMF) model of the nuclear matter equation of state was modified by including the effect of Pauli-blocking owing to quark exchange between the baryons. Different schemes of a chiral enhancement of the quark Pauli blocking was suggested according to the adopted density dependence of the dynamical quark mass. The resulting equations of state for the pressure are compared to the RMF model DD2 with excluded volume correction. On the basis of this comparison a density-dependent nucleon volume is extracted which parameterizes the quark Pauli blocking effect in the respective scheme of chiral enhancement. The dependence on the isospin asymmetry is investigated and the corresponding density dependent nuclear symmetry energy is obtained in fair accordance with phenomenological constraints. The deconfinement phase transition is obtained by a Maxwell construction with a quark matter phase described within a higher order NJL model. Solutions for rotating and nonrotating (hybrid) compact star sequences are obtained, which show the effect of high-mass twin compact star solutions for the rotating case.

Skyrme–Hartree–Fock–Bogoliubov Calculations of Even and Odd Neutron-Rich Mg Isotopes

2021 ◽  
Vol 66 (11) ◽  
pp. 928
Author(s):  
A.H. Taqi ◽  
M.A. Hasan
Keyword(s):  
Experimental Data ◽  
Mean Field ◽  
Field Method ◽  
Hartree Fock ◽  
Relativistic Mean Field ◽  
Nuclear Models ◽  
Quadrupole Deformation Parameter ◽  
Mg Isotopes ◽  
The One ◽  
Rmf Model

Using the Skyrme functional with SIII, SKM*, SLy4, and UNE0 sets of parameters and the Hartree–Fock–Bogoliubov mean-field method; the ground-state properties of even-even and even-odd neutron-rich Mg isotopes have been investigated. The results of calculations of the binding energy per nucleon (B/A), the one- and two-neutron separation energies (Sn and S2n), proton and neutron rms radii, neutron pairing gap, and quadrupole deformation parameter (B2) have been compared with the available experimental data, the results of Hartree–Fock–Bogoliubov calculations based on the D1S Gogny force, and predictions of some nuclear models such as the Finite Range Droplet Model (FRDM) and Relativistic Mean-Field (RMF) model. Our results show good agreements in comparison with the experimental data and the results of the mentioned models.

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