scholarly journals ASYMMETRIC NUCLEAR MATTER: A VARIATIONAL APPROACH

2008 ◽  
Vol 22 (25n26) ◽  
pp. 4524-4537 ◽  
Author(s):  
S. SARANGI ◽  
P. K. PANDA ◽  
S. K. SAHU ◽  
L. MAHARANA
Keyword(s):  
Nuclear Matter ◽  
Nucleon Nucleon ◽  
S Wave ◽  
Asymmetric Nuclear Matter ◽  
Saturation Properties ◽  
Equilibrium Binding ◽  
Self Consistent ◽  
Pure Neutron Matter ◽  
Consistent Method ◽  
Tov Equation

We discuss here a self-consistent method to calculate the properties of the cold asymmetric nuclear matter. In this model, the nuclear matter is dressed with s-wave pion pairs and the nucleon-nucleon (N-N) interaction is mediated by these pion pairs, ω and ρ mesons. The parameters of these interactions are calculated self-consistently to obtain the saturation properties like equilibrium binding energy, pressure, compressibility and symmetry energy. The computed equation of state is then used in the Tolman-Oppenheimer-Volkoff (TOV) equation to study the mass and radius of a neutron star in the pure neutron matter limit.

EQUATION OF STATE OF ASYMMETRIC NUCLEAR MATTER WITH GOGNY AND COULOMB INTERACTIONS

1990 ◽  
Vol 05 (14) ◽  
pp. 1071-1080 ◽  
Author(s):  
S. W. HUANG ◽  
M. Z. FU ◽  
S. S. WU ◽  
S. D. YANG
Keyword(s):  
Equation Of State ◽  
Nuclear Matter ◽  
Coulomb Interaction ◽  
Chemical Potential ◽  
Compression Modulus ◽  
Nucleon Nucleon ◽  
Effective Density ◽  
Coulomb Interactions ◽  
Asymmetric Nuclear Matter ◽  
Nucleon Nucleon Interaction

The equation of state of the asymmetric nuclear matter is calculated with the Gogny D1 effective density-dependent nucleon-nucleon interaction and the Coulomb interaction in the framework of the finite-temperature HF method with the rearrangement term. The dependence of the thermodynamical properties such as the critical temperature of the liquid-gas phase transition, the chemical potential, the compression modulus and the entropy on the Coulomb interaction in nuclear matter is treated by using a shielded two-body Coulomb potential and this method has been found to be a reasonable and effective approach.

scholarly journals Isospin Physics in Heavy-Ion Collisions at Intermediate Energies

1998 ◽  
Vol 07 (02) ◽  
pp. 147-229 ◽  
Author(s):  
Bao-An Li ◽  
Che Ming Ko ◽  
Wolfgang Bauer
Keyword(s):  
Equation Of State ◽  
Nuclear Matter ◽  
Cross Sections ◽  
Heavy Ion Collisions ◽  
Transport Model ◽  
Transient State ◽  
Heavy Ion ◽  
Nucleon Nucleon ◽  
Asymmetric Nuclear Matter ◽  
Ion Collisions

In nuclear collisions induced by stable or radioactive neutron-rich nuclei a transient state of nuclear matter with an appreciable isospin asymmetry as well as thermal and compressional excitation can be created. This offers the possibility to study the properties of nuclear matter in the region between symmetric nuclear matter and pure neutron matter. In this review, we discuss recent theoretical studies of the equation of state of isospin-asymmetric nuclear matter and its relations to the properties of neutron stars and radioactive nuclei. Chemical and mechanical instabilities as well as the liquid-gas phase transition in asymmetric nuclear matter are investigated. The in-medium nucleon-nucleon cross sections at different isospin states are reviewed as they affect significantly the dynamics of heavy ion collisions induced by radioactive beams. We then discuss an isospin-dependent transport model, which includes different mean-field potentials and cross sections for the proton and neutron, and its application to these reactions. Furthermore, we review the comparisons between theoretical predictions and available experimental data. In particular, we discuss the study of nuclear stopping in terms of isospin equilibration, the dependence of nuclear collective flow and balance energy on the isospin-dependent nuclear equation of state and cross sections, the isospin dependence of total nuclear reaction cross sections, and the role of isospin in preequilibrium nucleon emissions and subthreshold pion production.

scholarly journals The Equation of State for the Nucleonic and Hyperonic Core of Neutron Stars

2017 ◽  
Vol 34 ◽  
Author(s):  
Laura Tolos ◽  
Mario Centelles ◽  
Angels Ramos
Keyword(s):  
Equation Of State ◽  
Neutron Stars ◽  
Nuclear Matter ◽  
Inner Core ◽  
Heavy Ion ◽  
Saturation Properties ◽  
Ion Collisions ◽  
Pure Neutron Matter ◽  
Finite Nuclei ◽  
The Impact

AbstractWe re-examine the equation of state for the nucleonic and hyperonic inner core of neutron stars that satisfies the 2M⊙ observations as well as the recent determinations of stellar radii below 13 km, while fulfilling the saturation properties of nuclear matter and finite nuclei together with the constraints on the high-density nuclear pressure coming from heavy-ion collisions. The recent nucleonic FSU2R and hyperonic FSU2H models are updated in order to improve the behaviour of pure neutron matter at subsaturation densities. The corresponding nuclear matter properties at saturation, the symmetry energy, and its slope turn out to be compatible with recent experimental and theoretical determinations. We obtain the mass, radius, and composition of neutron stars for the two updated models and study the impact on these properties of the uncertainties in the hyperon–nucleon couplings estimated from hypernuclear data. We find that the onset of appearance of each hyperon strongly depends on the hyperon–nuclear uncertainties, whereas the maximum masses for neutron stars differ by at most 0.1M⊙, although a larger deviation should be expected tied to the lack of knowledge of the hyperon potentials at the high densities present in the centre of 2M⊙ stars. For easier use, we provide tables with the results from the FSU2R and FSU2H models for the equation of state and the neutron star mass–radius relation.

Quark degrees of freedom and nuclear matter saturation

2019 ◽  
Vol 34 (39) ◽  
pp. 1950322
Author(s):  
Marcello Baldo ◽  
Zahra Asadi Aghbolaghi ◽  
Isaac Vidaña ◽  
Mohsen Bigdeli
Keyword(s):  
Nuclear Matter ◽  
Degrees Of Freedom ◽  
Nucleon Nucleon ◽  
Meson Exchange ◽  
Nucleon Interaction ◽  
S Wave ◽  
Nucleon Potential ◽  
Quark Interaction ◽  
Exchange Processes ◽  
Nucleon Nucleon Interaction

It has been found in previous works [M. Baldo and K. Fukukawa, Phys. Rev. Lett. 113, 241501 (2014); K. Fukukawa, M. Baldo, G. F. Burgio, L. Lo Monaco and H.-J. Schulze, Phys. Rev. 92, 065802 (2015)] that the nucleon–nucleon potential of [Y. Fujiwara, M. Kohno, C. Nakamoto and Y. Suzuki Phys. Rev. C 64, 054001 (2001); Y. Fujiwara et al., Phys. Rev. C 65, 014002 (2001)] gives an accurate saturation point in symmetric nuclear matter once the three hole-line contributions are included in the Brueckner–Bethe–Goldstone expansion without the addition of three-body forces in the nuclear Hamiltonian. The potential is based on a quark model of nucleons and on the quark–quark interaction together with quark exchange processes. These features introduce an intrinsic nonlocality of the nucleon–nucleon interaction. In order to clarify the role of the quark degrees of freedom and of the nonlocality in the saturation, we perform a comparative study of this potential and the traditional meson exchange models, exemplified in the CD-Bonn potential. We find that at the Brueckner–Hartree–Fock approximation, which corresponds to the two hole-line level of approximation, the dominant modification of the nucleon–nucleon interaction with respect to CD-Bonn is incorporated in the s-wave channels, where the quark degrees of freedom should be more relevant, in particular for the short range quark exchange processes. However, when the three hole-line contribution is included, we find that the higher partial waves play a relevant role, mainly in the term that describes the effect of the medium on the off-shell propagation of the nucleon.

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