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 THE MODIFICATION OF THE SCALAR FIELD IN DENSE NUCLEAR MATTER

2010 ◽  
Vol 19 (04) ◽  
pp. 774-780
Author(s):  
JACEK ROŻYNEK
Keyword(s):  
Structure Function ◽  
Nuclear Matter ◽  
Mean Field ◽  
Nuclear Interaction ◽  
Nucleon Structure ◽  
Saturation Point ◽  
Relativistic Mean Field ◽  
Convolution Model ◽  
Dense Nuclear Matter ◽  
Nucleon Structure Function

We show the possible evolution of the nuclear deep inelastic structure function with nuclear density ρ. The nucleon deep inelastic structure function represents distribution of quarks as a function of Björken variable x, which measures the longitudinal fraction of the momentum carried by them during deep inelastic scattering (DIS) of electrons on nuclear targets. The quark localization is proportional to 1/x and this relation introduces the dependence of the nucleon structure function on the nuclear medium. Starting with small density and negative pressure in nuclear matter (NM), we have relatively large inter-nucleon distances and increasing role of nuclear interaction mediated by virtual mesons. When the density approaches the saturation point, ρ = ρ0, we have no longer separate mesons and nucleons but eventually modified nucleon structure function (SF) in the medium. The ratio of the nuclear to the nucleon SF measured at the saturation point is well known as the "EMC effect". For larger density, ρ > ρ0, when the localization of quarks is smaller than 0.3 fm, the nucleons overlap. We argue that nucleon mass should start to decrease in order to satisfy the momentum sum rule (MSR) of DIS. These modifications of the nucleon structure function are calculated in the frame of the nuclear relativistic mean field (RMF) convolution model. The correction to the Fermi energy from a term proportional to the pressure is very important and its inclusion modifies the equation of state (EoS) for the nuclear matter.

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.

HOT NUCLEAR MATTER PROPERTIES

2007 ◽  
Vol 16 (09) ◽  
pp. 3041-3044
Author(s):  
TOMAZ PASSAMANI ◽  
MARIA LUIZA CESCATO
Keyword(s):  
Field Theory ◽  
Equation Of State ◽  
Nuclear Matter ◽  
Finite Temperature ◽  
Mean Field Theory ◽  
Mean Field ◽  
Nonlinear Interactions ◽  
Nucleon Mass ◽  
Relativistic Mean Field ◽  
Linear And Nonlinear

The nuclear matter at finite temperature is described in the relativistic mean field theory using linear and nonlinear interactions. The behavior of effective nucleon mass with temperature was numerically calculated. For the nonlinear NL3 interaction we also observed the striking decrease at temperatures well below the nucleon mass. The calculation of NL3 nuclear matter equation of state at finite temperature is still on progress.

IMPORTANCE OF THE π-FIELD IN THE RELATIVISTIC MEAN FIELD THEORY FOR NUCLEAR MATTER

1995 ◽  
Vol 10 (37) ◽  
pp. 2809-2818 ◽  
Author(s):  
QI-REN ZHANG ◽  
WALTER GREINER
Keyword(s):  
Field Theory ◽  
Equation Of State ◽  
Nuclear Matter ◽  
Mean Field Theory ◽  
Mean Field ◽  
Relativistic Mean Field Theory ◽  
Relativistic Mean Field ◽  
Nuclear Equation Of State ◽  
Walecka Model

We generalize the Walecka model for nuclear matter by including the π-field. It is found that a finite mean π-field may lower the energy per nucleon even in the nuclear matter of subnormal density. A mean π-field may significantly change the nuclear equation of state. The importance of considering the π-field in the relativistic mean field theory for nuclear matter is therefore emphasized.

STRUCTURE FUNCTION IN NUCLEAR MATTER IN THE NJL MODEL

2003 ◽  
Vol 18 (02n06) ◽  
pp. 384-387
Author(s):  
H. MINEO ◽  
W. BENTZ ◽  
A. W. THOMAS ◽  
N. ISHII ◽  
K. YAZAKI
Keyword(s):  
Experimental Data ◽  
Equation Of State ◽  
Structure Function ◽  
Nuclear Matter ◽  
Structure Functions ◽  
Simple Approximation ◽  
Nucleon Structure ◽  
Confinement Effects ◽  
Njl Model ◽  
Emc Effect

In this work we discuss the EMC effect on the nucleon structure functions in nuclear matter, using a simple approximation to the relativistic Faddeev description of the nucleon in the framework of the Nambu-Jona-Lasinio (NJL) model. We adopt a stable nuclear matter equation of state, calculated in the NJL model, which incorporates confinement effects phenomenologically so as to avoid unphysical thresholds for the decay into quarks. We will compare our results for the EMC ratio in nuclear matter in the NJL model with the parametrized fits to the experimental data.

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.

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.

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