INSTABILITIES CONSTRAINT AND RELATIVISTIC MEAN FIELD PARAMETRIZATION

2011 ◽  
Vol 20 (01) ◽  
pp. 81-100 ◽  
Author(s):  
A. SULAKSONO ◽  
KASMUDIN ◽  
T. J. BÜRVENICH ◽  
P.-G. REINHARD ◽  
J. A. MARUHN
Keyword(s):  
Experimental Data ◽  
Equation Of State ◽  
Nuclear Matter ◽  
Nonlinear Term ◽  
Mean Field ◽  
Saturation Point ◽  
Relativistic Mean Field ◽  
Finite Nuclei ◽  
Two Parameter ◽  
Rmf Model

Two parameter sets (Set 1 and Set 2) of the standard relativistic mean field (RMF) model plus additional vector isoscalar nonlinear term, which are constrained by a set of criteria20 determined by symmetric nuclear matter stabilities at high densities due to longitudinal and transversal particle–hole excitation modes are investigated. In the latter parameter set, δ meson and isoscalar as well as isovector tensor contributions are included. The effects in selected finite nuclei and nuclear matter properties predicted by both parameter sets are systematically studied and compared with the ones predicted by well-known RMF parameter sets. The vector isoscalar nonlinear term addition and instability constraints have reasonably good effects in the high-density properties of the isoscalar sector of nuclear matter and certain finite nuclei properties. However, even though the δ meson and isovector tensor are included, the incompatibility with the constraints from some experimental data in certain nuclear properties at saturation point and the excessive stiffness of the isovector nuclear matter equation of state at high densities as well as the incorrect isotonic trend in binding the energies of finite nuclei are still encountered. It is shown that the problem may be remedied if we introduce additional nonlinear terms not only in the isovector but also in the isoscalar vectors.

RELATIVISTIC MEAN FIELD THEORY FOR UNSTABLE NUCLEI AND SUPERNOVAE

2003 ◽  
Vol 17 (28) ◽  
pp. 5175-5184
Author(s):  
HIROSHI TOKI
Keyword(s):  
Field Theory ◽  
Experimental Data ◽  
Equation Of State ◽  
Mean Field Theory ◽  
Mean Field ◽  
Microscopic Theory ◽  
Phenomenological Theory ◽  
Relativistic Mean Field ◽  
Unstable Nuclei ◽  
Finite Nuclei

We discuss first the properties of unstable nuclei in the framework of the relativistic mean field (RMF) theory. We take the RMF theory as a phenomenological theory with several parameters, whose form is constrained by the successful microscopic theory (RBHF), and whose values are extracted from the experimental data of unstable nuclei. We find the outcome with the use of the parameter sets (TM1 and TMA) is promising in comparison with various experimental data on finite nuclei including unstable ones. We construct then the equation of state of nuclear matter for the use in the description of supernovae. We present also the simulations of supernovae with the supernova newly constructed equation of state in the prompt explosion scenario.

scholarly journals Nucleon properties inside the compressed nuclear matter

2018 ◽  
Vol 27 (04) ◽  
pp. 1850030
Author(s):  
Jacek Rożynek
Keyword(s):  
Energy Transfer ◽  
Equation Of State ◽  
Nuclear Matter ◽  
Symmetry Energy ◽  
Mean Field ◽  
Equilibrium Density ◽  
Nucleon Mass ◽  
Relativistic Mean Field ◽  
Rmf Model

In this work, we show the modifications of nucleon mass and nucleon radius with the help of the extended Relativistic Mean Field (RMF) model. We argue that even small departures above nuclear equilibrium density with constant nucleon mass require an energy transfer from the repulsive mean field to the quarks forming nucleon massive bags in Nuclear Matter (NM), together with the decrease in the nucleon volume. The transfer, which is proportional to pressure and absent in a standard RMF approach, provides good values for nuclear compressibility, symmetry energy and its slope. Different courses of the Equation of State (EOS), which depend on the energy transfer, are considered.

HYPERON DENSITY DEPENDENCE OF HYPERON-NUCLEON INTERACTIONS IN NEUTRON STARS

2008 ◽  
Vol 17 (09) ◽  
pp. 1720-1728
Author(s):  
L. DANG ◽  
P. YUE ◽  
L. LI ◽  
P. Z. NING
Keyword(s):  
Equation Of State ◽  
Neutron Stars ◽  
Density Dependence ◽  
Mean Field ◽  
Density Dependent ◽  
Effective Potentials ◽  
Relativistic Mean Field ◽  
Nucleon Interactions ◽  
Dependent Factor ◽  
Rmf Model

The hyperon density dependence (YDD) of hyperon-nucleon interactions are studied in the relativistic mean field (RMF) model and their influences on the properties of neutron stars are studied. The extended RMF considered the interior quarks coordinates of hyperon and bring a hyperon density dependent factor, f(ρY), to the meson-hyperon coupling vertexes. The hyperon density dependence of YN interaction affect the properties of neutron stars only after the corresponding hyperon appears. Then, the influences of the density dependence factors are almost ignored at low densities, which are clear at high densities. The compositions and properties of neutron stars are studied with and without the YDD of YN interactions for the different Σ--nucleus effective potentials, (30, 0, -30)MeV. The calculated results indicated that the YDD of YN interaction soften the equation of state of neutron stars at high densities.

ELECTROMAGNETIC AND ISOVECTOR TERMS IN STANDARD RELATIVISTIC MEAN FIELD MODEL

2011 ◽  
Vol 20 (09) ◽  
pp. 1983-2010 ◽  
Author(s):  
A. SULAKSONO
Keyword(s):  
Nuclear Matter ◽  
Field Model ◽  
Local Density ◽  
Mean Field ◽  
Binding Energies ◽  
Particle Spectrum ◽  
Mean Field Model ◽  
Density Dependent ◽  
Relativistic Mean Field ◽  
Finite Nuclei

The effects of auxiliary contribution in forms of electromagnetic tensors and relativistic electromagnetic exchange in local density approximation as well as δ meson and isovector density-dependent nonlinear terms in standard relativistic mean field model constrained by nuclear matter stability criteria in some selected finite nuclei and nuclear matter properties are studied. It is found that in the case of finite nuclei, the electromagnetic tensors play the most dominant part compared to other auxiliary terms. Due to the presence of electromagnetic tensors, the binding energies prediction of the model can be improved quite significantly. However, these terms do not yield demanded effects for rms radii prediction. In the case of nuclear matter properties, the isovector density-dependent nonlinear term plays the most crucial role in providing predictions which are quite compatible with experimental constraints. We have also shown these auxiliary contributions are indeed unable to improve the single particle spectrum results of the model.

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.

THE NUCLEON STRUCTURE AND THE EQUATION OF STATE FOR NUCLEAR MATTER

2007 ◽  
Vol 16 (02) ◽  
pp. 608-615
Author(s):  
J. ROŻYNEK
Keyword(s):  
Equation Of State ◽  
Structure Function ◽  
Nuclear Matter ◽  
Mean Field ◽  
Nucleon Structure ◽  
Final State ◽  
Rest Energy ◽  
Relativistic Mean Field ◽  
Quark Contribution ◽  
Nucleon Structure Function

We show the density dependent corrections to the nucleon structure function in the frame of nuclear Relativistic Mean Field (RMF) models. These corrections are connected with the modifications of the parton distribution in nuclei emerging from generalized nuclear Fermi motion and final state interactions between the nucleon and the rest of the nucleus. The medium effects concern the nucleon structure, namely the changes in the nucleon rest energy, the enhancement of sea quark contribution (simulated with "nuclear pions") and the modifications of the transverse parton momentum distribution inside Nuclear Matter (NM). The sea parton distributions are described by the modified cloud of virtual pions in order to saturate the nuclear energy-momentum sum rule. The description of theses features are in good agreement with experimental data; the EMC effect for x > 0.15 and nuclear lepton pair production data has been described essentialy without free parameters. The influence of these medium modifications to the nucleon structure function within the equation of state in RMF models of NM will be discussed.

scholarly journals A Modern View of the Equation of State in Nuclear and Neutron Star Matter

Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 400
Author(s):  
G. Fiorella Burgio ◽  
Hans-Josef Schulze ◽  
Isaac Vidaña ◽  
Jin-Biao Wei
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Nuclear Matter ◽  
Symmetry Energy ◽  
Quantum Monte Carlo ◽  
Mean Field ◽  
Nuclear Symmetry Energy ◽  
Relativistic Mean Field ◽  
Monte Carlo Techniques ◽  
Nuclear Incompressibility

Background: We analyze several constraints on the nuclear equation of state (EOS) currently available from neutron star (NS) observations and laboratory experiments and study the existence of possible correlations among properties of nuclear matter at saturation density with NS observables. Methods: We use a set of different models that include several phenomenological EOSs based on Skyrme and relativistic mean field models as well as microscopic calculations based on different many-body approaches, i.e., the (Dirac–)Brueckner–Hartree–Fock theories, Quantum Monte Carlo techniques, and the variational method. Results: We find that almost all the models considered are compatible with the laboratory constraints of the nuclear matter properties as well as with the largest NS mass observed up to now, 2.14−0.09+0.10M⊙ for the object PSR J0740+6620, and with the upper limit of the maximum mass of about 2.3–2.5M⊙ deduced from the analysis of the GW170817 NS merger event. Conclusion: Our study shows that whereas no correlation exists between the tidal deformability and the value of the nuclear symmetry energy at saturation for any value of the NS mass, very weak correlations seem to exist with the derivative of the nuclear symmetry energy and with the nuclear incompressibility.

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