scholarly journals THE MICROSCOPIC APPROACH TO NUCLEAR MATTER AND NEUTRON STAR MATTER

2010 ◽  
Vol 19 (07) ◽  
pp. 1259-1313 ◽  
Author(s):  
FRANCESCA SAMMARRUCA
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Nuclear Matter ◽  
Symmetry Energy ◽  
Heavy Ion ◽  
Experimental Investigations ◽  
Common Denominator ◽  
Neutron Skin ◽  
Microscopic Approach ◽  
Ion Collisions

We review a variety of theoretical and experimental investigations aimed at improving our knowledge of the nuclear matter equation of state. Of particular interest are nuclear matter extreme states in terms of density and/or isospin asymmetry. The equation of state of matter with unequal concentrations of protons and neutrons has numerous applications. These include heavy-ion collisions, the physics of rare, short-lived nuclei and, on a dramatically different scale, the physics of neutron stars. The "common denominator" among these (seemingly) very different systems is the symmetry energy, which plays a crucial role in both the formation of the neutron skin in neutron-rich nuclei and the radius of a neutron star (a system 18 orders of magnitude larger and 55 orders of magnitudes heavier). The details of the density dependence of the symmetry energy are not yet sufficiently constrained. Throughout this article, our emphasis will be on the importance of adopting a microscopic approach to the many-body problem, which we believe to be the one with true predictive power.

scholarly journals TRANSITION DENSITY AND PRESSURE AT THE INNER EDGE OF NEUTRON STAR CRUSTS

2010 ◽  
Vol 19 (08n09) ◽  
pp. 1705-1711
Author(s):  
JUN XU ◽  
CHE MING KO ◽  
LIE-WEN CHEN ◽  
BAO-AN LI ◽  
HONG-RU MA
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Neutron Stars ◽  
Symmetry Energy ◽  
Transition Density ◽  
Heavy Ion ◽  
Intermediate Energy ◽  
Nuclear Symmetry Energy ◽  
Parabolic Approximation ◽  
Ion Collisions

Using the nuclear symmetry energy that has been recently constrained by the isospin diffusion data in intermediate-energy heavy ion collisions, we have studied the transition density and pressure at the inner edge of neutron star crusts, and they are found to be 0.040 fm -3 ≤ ρt ≤ 0.065 fm -3 and 0.01 MeV / fm 3 ≤ Pt ≤ 0.26 MeV / fm 3, respectively, in both the dynamical and thermodynamical approaches. We have also found that the widely used parabolic approximation to the equation of state of asymmetric nuclear matter gives significantly higher values of core-crust transition density and pressure, especially for stiff symmetry energies. With these newly determined transition density and pressure, we have obtained an improved relation between the mass and radius of neutron stars.

scholarly journals Constraints on EOS from finite nuclei, heavy ion collisions and neutron stars

2020 ◽  
Vol 15 ◽  
pp. 196
Author(s):  
T. Gaitanos ◽  
G. Ferini ◽  
M. Colonna ◽  
M. Di Toro ◽  
G. A. Lalazissis ◽  
...  
Keyword(s):  
Equation Of State ◽  
Neutron Stars ◽  
Symmetry Energy ◽  
Ground State ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Intermediate Energy ◽  
Ion Collisions ◽  
Finite Nuclei ◽  
Asymmetric Matter

We present several possibilities offered by nuclear structure, the dynamics of intermediate energy heavy ion collisions and neutron stars to investigate the nuclear matter equation of state (EoS) beyond the ground state. In particular the high density nuclear EoS of asymmetric matter, i.e. the symmetry energy, is discussed.

scholarly journals The Nuclear Equation of State in Heavy Ion Collisions

2020 ◽  
Vol 13 ◽  
pp. 203
Author(s):  
T. Gaitanos ◽  
M. Colonna ◽  
M. Di Toro ◽  
H. H. Wolter
Keyword(s):  
Equation Of State ◽  
Nuclear Matter ◽  
Ground State ◽  
Heavy Ion Collisions ◽  
Reaction Dynamics ◽  
Heavy Ion ◽  
Intermediate Energy ◽  
Nuclear Equation Of State ◽  
Ion Collisions ◽  
Theoretical Results

We present several possibilities offered by the dynamics of intermediate energy heavy ion collisions to investigate the nuclear matter equation of state (EoS) beyond the ground state. In particular the relation between the reaction dynamics and the high density nuclear EoS is discussed by comparing theoretical results with experiments.

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.

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.

scholarly journals Upgrading the Baryonic Matter at the Nuclotron Experiment at NICA for Studies of Dense Nuclear Matter

Particles ◽  
2019 ◽  
Vol 2 (4) ◽  
pp. 481-490
Author(s):  
Peter Senger ◽  
Dmitrii Dementev ◽  
Johann Heuser ◽  
Mikhail Kapishin ◽  
Evgeny Lavrik ◽  
...  
Keyword(s):  
Neutron Star ◽  
Nuclear Matter ◽  
Nuclear Research ◽  
Feasibility Studies ◽  
Heavy Ion ◽  
High Density ◽  
Baryonic Matter ◽  
Ion Collisions ◽  
Dense Nuclear Matter ◽  
Density Equation

The Nuclotron at the Joint Institute for Nuclear Research in Dubna can deliver gold beams with kinetic energies between 2 and 4.5 A GeV. In heavy-ion collisions at these energies, it is expected that the nuclear fireball will be compressed by up to approximately four times the saturation density. This offers the opportunity to study the high-density equation-of-state (EOS) of nuclear matter in the laboratory, which is needed for our understanding of the structure of neutron stars and the dynamics of neutron star mergers. The Baryonic Matter at the Nuclotron (BM@N) experiment will be upgraded to perform multi-differential measurements of hadrons including (multi-) strange hyperons, which are promising probes of the high-density EOS, and of new phases of quantum chromodynamic (QCD) matter. The layout of the upgraded BM@N experiment and the results of feasibility studies are presented.

The symmetry energy: Predictions and constraints

2017 ◽  
Vol 32 (30) ◽  
pp. 1730027 ◽  
Author(s):  
Francesca Sammarruca
Keyword(s):  
Neutron Star ◽  
Symmetry Energy ◽  
Heavy Ion ◽  
Skin Thickness ◽  
Neutron Skin ◽  
Nuclear Forces ◽  
Neutron Skin Thickness ◽  
Density Derivative ◽  
Proper Consideration ◽  
Future Plans

After recalling basic phenomenological features of isospin asymmetric nuclear matter, we review predictions for the interaction part of the symmetry energy obtained from different microscopic approaches. The predictions are compared to updated constraints extracted from heavy-ion (HI) reaction observables of a recent GSI experiment. The discussion is extended to the neutron skin thickness in [Formula: see text] and its relation to the density derivative of the symmetry energy. We underline the importance of giving proper consideration to the theoretical uncertainties of microscopic predictions in order to guide phenomenological analyses. In the end, we report briefly on preliminary neutron star calculations based on chiral nuclear forces and outline future plans.

scholarly journals Probing Dense Nuclear Matter in the Laboratory: Experiments at FAIR and NICA

Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 171
Author(s):  
Peter Senger
Keyword(s):  
Phase Transition ◽  
Neutron Star ◽  
Neutron Stars ◽  
Nuclear Matter ◽  
Quark Matter ◽  
Heavy Ion Collisions ◽  
Laboratory Experiments ◽  
Heavy Ion ◽  
High Density ◽  
Ion Collisions

The poorly known properties of high-density strongly-interacting matter govern the structure of neutron stars and the dynamics of neutron star mergers. New insight has been and will be gained by astronomical observations, such as the measurement of mass and radius of neutron stars, and the detection of gravitational waves emitted from neutron star mergers. Alternatively, information on the Nuclear Matter Equation-of-State (EOS) and on a possible phase transition from hadronic to quark matter at high baryon densities can be obtained from laboratory experiments investigating heavy-ion collisions. Detector systems dedicated to such experiments are under construction at the “Facility for Antiproton and Ion Research” (FAIR) in Darmstadt, Germany, and at the “Nuclotron-based Ion Collider fAcility” (NICA) in Dubna, Russia. In heavy-ion collisions at these accelerator centers, one expects the creation of baryon densities of up to 10 times saturation density, where quark degrees-of-freedom should emerge. This article reviews the most promising observables in heavy-ion collisions, which are used to probe the high-density EOS and possible phase transition from hadronic to quark matter. Finally, the facilities and the experimental setups will be briefly described.

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