SPEED OF SOUND IN NUCLEAR MATTER AND SKYRME EFFECTIVE INTERACTIONS

1987 ◽  
Vol 02 (02) ◽  
pp. 71-79 ◽  
Author(s):  
R.K. SU ◽  
T.T.S. KUO
Keyword(s):  
Equation Of State ◽  
Nuclear Matter ◽  
Speed Of Sound ◽  
Finite Temperature ◽  
Function Method ◽  
Effective Interaction ◽  
Similar Calculation ◽  
Effective Interactions ◽  
Nuclear Equation Of State ◽  
Temperature Green’S Function

Using a nuclear equation of state derived from a finite-temperature Green’s function method and the Skyrme effective interactions SkI, SkIII and SkM*, we have calculated the speed of sound in symmetric nuclear matter. For certain densities and temperatures, this speed is found to become super-luminous. Causal boundaries in the density-temperature plane are determined, and they indicate that SkM* is a more desirable effective interaction than SkI and SkIII. Comparison with a similar calculation by Osnes and Strottman is made.

CRITICAL NEUTRON-PROTON ASYMMETRY OF HOT NUCLEAR MATTER

1986 ◽  
Vol 01 (02) ◽  
pp. 71-80 ◽  
Author(s):  
R.K. SU ◽  
S.D. YANG ◽  
G.L. LI ◽  
T.T.S. KUO
Keyword(s):  
Nuclear Matter ◽  
Finite Temperature ◽  
Mean Field ◽  
Nucleon Nucleon ◽  
Nucleon Interaction ◽  
Effective Interactions ◽  
Normal Pair ◽  
Nucleon Nucleon Interaction ◽  
Density Equation ◽  
Temperature Green’S Function

We derive an equation of state for asymmetric nuclear matter at finite temperature, using the Skyrme effective nucleon-nucleon interaction and a mean field approach based on a real-time finite temperature Green’s function method with a normal pair cutoff approximation. With the temperature held constant, it is found that nuclear matter can exist only in the gaseous phase when its neutron excess coefficient a has surpassed a certain critical value αc. We have calculated αc for a number of different Skyrme effective interactions. Phase diagrams involving a are obtained, and a low-density equation for the phase boundary is derived.

scholarly journals Nuclear equation of state and neutron star cooling

2017 ◽  
Vol 26 (04) ◽  
pp. 1750015 ◽  
Author(s):  
Yeunhwan Lim ◽  
Chang Ho Hyun ◽  
Chang-Hwan Lee
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Neutron Stars ◽  
Nuclear Matter ◽  
Thermal Evolution ◽  
Observation Data ◽  
Nuclear Equation Of State ◽  
The Core ◽  
Dense Nuclear Matter ◽  
Nuclear Models

In this paper, we investigate the cooling of neutron stars with relativistic and nonrelativistic models of dense nuclear matter. We focus on the effects of uncertainties originated from the nuclear models, the composition of elements in the envelope region, and the formation of superfluidity in the core and the crust of neutron stars. Discovery of [Formula: see text] neutron stars PSR J1614−2230 and PSR J0343[Formula: see text]0432 has triggered the revival of stiff nuclear equation of state at high densities. In the meantime, observation of a neutron star in Cassiopeia A for more than 10 years has provided us with very accurate data for the thermal evolution of neutron stars. Both mass and temperature of neutron stars depend critically on the equation of state of nuclear matter, so we first search for nuclear models that satisfy the constraints from mass and temperature simultaneously within a reasonable range. With selected models, we explore the effects of element composition in the envelope region, and the existence of superfluidity in the core and the crust of neutron stars. Due to uncertainty in the composition of particles in the envelope region, we obtain a range of cooling curves that can cover substantial region of observation data.

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 EQUATION OF STATE FOR DENSE SUPERNOVA MATTER

2009 ◽  
Vol 18 (08) ◽  
pp. 1205-1226 ◽  
Author(s):  
C. C. MOUSTAKIDIS
Keyword(s):  
High Temperature ◽  
Equation Of State ◽  
Nuclear Matter ◽  
Thermal Effects ◽  
Effective Interaction ◽  
Interaction Model ◽  
Decay Process ◽  
High Density ◽  
Β Decay ◽  
Charge Neutrality

We provide an equation of state for high density supernova matter by applying a momentum-dependent effective interaction. We focus on the study of the equation of state of high density and high temperature nuclear matter containing leptons (electrons and neutrinos) under the chemical equilibrium condition. The conditions of charge neutrality and equilibrium under the β-decay process lead first to the evaluation of the lepton fractions and afterward to the evaluation of internal energy, pressure, entropy and, in total to the equation of state of hot nuclear matter for various isothermal cases. Thermal effects on the properties and equation of state of nuclear matter are evaluated and analyzed in the framework of the proposed effective interaction model. Since supernova matter is characterized by a constant entropy, we also present the thermodynamic properties for the isentropic case. Special attention is devoted to the study of the contribution of the components of β-stable nuclear matter to the entropy per particle, a quantity of great interest for the study of structure and collapse of supernovas.

Delta and pion abundances in hot dense nuclear matter and the nuclear equation of state

1988 ◽  
Vol 201 (1) ◽  
pp. 11-16 ◽  
Author(s):  
M. Cubero ◽  
M. Schönhofen ◽  
H. Feldmeier ◽  
W. Nörenberg
Keyword(s):  
Equation Of State ◽  
Nuclear Matter ◽  
Nuclear Equation Of State ◽  
Dense Nuclear Matter

Hot Nuclear Matter Equation of State and Finite Temperature Kaon Condensation

2008 ◽  
Vol 25 (12) ◽  
pp. 4233-4236 ◽  
Author(s):  
Li Ang ◽  
Zuo Wei ◽  
H. J Schulze ◽  
U Lombardo
Keyword(s):  
Equation Of State ◽  
Nuclear Matter ◽  
Finite Temperature ◽  
Kaon Condensation

scholarly journals VIRIAL EXPANSION OF THE NUCLEAR EQUATION OF STATE

2012 ◽  
Vol 21 (01) ◽  
pp. 1250006 ◽  
Author(s):  
RUSLAN MAGANA ◽  
HUA ZHENG ◽  
ALDO BONASERA
Keyword(s):  
Phase Transition ◽  
Equation Of State ◽  
Nuclear Matter ◽  
Order Phase Transition ◽  
Quark Gluon Plasma ◽  
Ground State ◽  
Gluon Plasma ◽  
Second Order ◽  
Nuclear Equation Of State ◽  
Second Order Phase Transition

We study the equation of state (EOS) of nuclear matter as function of density. We expand the energy per particle (E/A) of symmetric infinite nuclear matter in powers of the density to take into account 2, 3, …, N-body forces. New EOS are proposed by fitting ground state properties of nuclear matter (binding energy, compressibility and pressure) and assuming that at high densities a second-order phase transition to the quark–gluon plasma (QGP) occurs. The latter phase transition is due to symmetry breaking at high density from nuclear matter (locally color white) to the QGP (globally color white). In the simplest implementation of a second-order phase transition we calculate the critical exponent δ by using Landau's theory of phase transition. We find δ = 3. Refining the properties of the EOS near the critical point gives δ = 5 in agreement with experimental results. We also discuss some scenarios for the EOS at finite temperatures.

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