scholarly journals Liquid-gas phase transition in nuclear matter in the mean-field approximation

2011 ◽  
Vol 321 ◽  
pp. 012058
Author(s):  
A Rios ◽  
A Carbone ◽  
A Polls ◽  
I Vidaña
Keyword(s):  
Phase Transition ◽  
Nuclear Matter ◽  
Gas Phase ◽  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
The Mean

Quartetting in Fermionic Matter and Alpha-Particle Condensation in Nuclear Systems

2006 ◽  
Vol 21 (31n33) ◽  
pp. 2513-2546 ◽  
Author(s):  
G. Röpke ◽  
P. Schuck
Keyword(s):  
Nuclear Matter ◽  
Cluster Formation ◽  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Density Region ◽  
Nuclear Matter Density ◽  
Nuclear Systems ◽  
The Mean ◽  
Finite Nuclei

Quantum condensates in nuclear matter are treated beyond the mean-field approximation, with the inclusion of cluster formation. The occurrence of a separate binding pole in the four-particle propagator in nuclear matter is investigated with respect to the formation of a condensate of α-like particles (quartetting), which is dependent on temperature and density. Due to Pauli blocking, the formation of an α-like condensate is limited to the low-density region. Consequences for finite nuclei are considered. In particular, excitations of self-conjugate 2n-Z–2n-N nuclei near the n-α-breakup threshold are candidates for quartetting. We review some results and discuss their consequences. Exploratory calculations are performed for the density dependence of the α condensate fraction at zero temperature to address the suppression of the four-particle condensate below nuclear-matter density.

QUADRUPOLE DEFORMATION IN NUCLEI AT FINITE TEMPERATURE

1998 ◽  
Vol 13 (33) ◽  
pp. 2705-2713 ◽  
Author(s):  
B. J. COLE ◽  
H. G. MILLER ◽  
R. M. QUICK
Keyword(s):  
Phase Transition ◽  
Finite Temperature ◽  
Mean Field ◽  
Field Approximation ◽  
Quadrupole Deformation ◽  
Mean Field Approximation ◽  
Zero Temperature ◽  
Average Deformation ◽  
The Mean ◽  
Shape Changes

The intrinsic quadrupole deformation has been calculated at finite temperature in 20 Ne both in the mean-field approximation and using an exact shell model diagonalization. The results support the view that the phase transition seen at finite temperature in mean-field calculations is not due to the change in nuclear shape from deformed to spherical, but rather is a collective-to-non-collective transition. Both calculations indicate that the average deformation of 20 Ne changes from β rms ≈0.31 at zero temperature to just over β rms =0.2 at T=3.0 MeV. The calculations also suggest that, in the mean-field approximation, the square of the quadrupole operator, Q[2]·Q[2], is a better indicator of shape changes than Q[2] itself.

THE MULTI-VALUE OF EFFECTIVE NUCLEON MASS IN HOT/DENSE NUCLEAR MATTER AND THE PHASE TRANSITION

2002 ◽  
Vol 17 (21) ◽  
pp. 1345-1353
Author(s):  
MENG JIN ◽  
JIARONG LI ◽  
JISHENG CHEN
Keyword(s):  
Phase Transition ◽  
Temperature Region ◽  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Nucleon Mass ◽  
High Temperature Region ◽  
Dense Nuclear Matter ◽  
The Mean ◽  
Consistent Equation

From the Lagrangian of QHD-I model, we investigate the effective nucleon mass under the mean field approximation in a wide temperature region. The multi-solution of self-consistent equation for the effective mass in found. In the high temperature region, the relation between the multi-solutions and the phase transition is analyzed. Furthermore, the variation of energy density in this region is studied.

scholarly journals DENSITY FLUCTUATIONS AND A FIRST-ORDER CHIRAL PHASE TRANSITION IN NON-EQUILIBRIUM

2008 ◽  
Vol 23 (27n30) ◽  
pp. 2469-2472 ◽  
Author(s):  
CHIHIRO SASAKI ◽  
BENGT FRIMAN ◽  
KRZYSZTOF REDLICH
Keyword(s):  
Phase Transition ◽  
Mean Field ◽  
Field Approximation ◽  
Density Fluctuations ◽  
Mean Field Approximation ◽  
Chiral Phase ◽  
Chiral Phase Transition ◽  
First Order ◽  
The Mean ◽  
Non Equilibrium

The thermodynamics of a first-order chiral phase transition is considered in the presence of spinodal phase separation using the Nambu-Jona-Lasinio model in the mean field approximation. We focus on the behavior of conserved charge fluctuations. We show that in non-equilibrium the specific heat and charge susceptibilities diverge as the system crosses the isothermal spinodal lines.

scholarly journals ALTERNATIVE LINEAR CHIRAL MODELS FOR NUCLEAR MATTER

1999 ◽  
Vol 14 (24) ◽  
pp. 1615-1623 ◽  
Author(s):  
A. DELFINO ◽  
F. S. NAVARRA ◽  
M. NIELSEN ◽  
R. B. PRANDINI ◽  
M. CHIAPPARINI
Keyword(s):  
Equation Of State ◽  
Nuclear Matter ◽  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Saturation Properties ◽  
The Mean

The equation of state of a family of alternative linear chiral models in the mean field approximation is discussed. We investigate the analogy between some of these models and current models in the literature, and we show that it is possible to reproduce very well the saturation properties of nuclear matter.

scholarly journals The Haus-Tanaka Model for the Ice VII-Ice VIII Phase Transition

1980 ◽  
Vol 33 (1) ◽  
pp. 107 ◽  
Author(s):  
J Ho-Ting-Hun ◽  
J Oitmaa
Keyword(s):  
Phase Transition ◽  
Mean Field ◽  
Field Approximation ◽  
Order Transition ◽  
Mean Field Approximation ◽  
First Order ◽  
Second Order Transition ◽  
The Mean ◽  
First Order Transition ◽  
Temperature Susceptibility

The high temperature susceptibility series of the model proposed by Haus and Tanaka (1977) to account for the transition of the orientationally disordered ice VII phase to the orientationally ordered ice VIII phase does not provide evidence for the possible occurrence of a first-order transition, as predicted by the mean field approximation, but gives a second-order transition instead.

scholarly journals ρ-MESON SPECTRAL FUNCTION IN HOT NUCLEAR MATTER

2012 ◽  
Vol 21 (06) ◽  
pp. 1250063 ◽  
Author(s):  
P. C. RAJE BHAGEERATHI
Keyword(s):  
Nuclear Matter ◽  
Spectral Function ◽  
Strong Dependence ◽  
Mean Field ◽  
Field Approximation ◽  
Mass Region ◽  
Mean Field Approximation ◽  
Qhd Model ◽  
The Mean ◽  
Second Peak

The ρ-meson spectral function in hot nuclear matter is studied by taking into account the pion and the nucleon loops within the quantum hadrodynamics (QHD) model as well as using an effective chiral SU(3) model. The effects of density and temperature on the spectral function of the ρ-meson are studied assuming the ρ-meson to be with a finite momentum. These investigations are performed using both the mean field approximation (MFA) and the relativistic Hartree (RHA) approximation. The inclusion of the nucleon loop is observed to considerably change the ρ-meson spectral function. Due to a larger mass drop of ρ-meson in the RHA, it is seen that the spectral function shifts towards the low invariant mass region, whereas in the MFA the spectral function is seen to be almost centered around the nominal ρ-pole, but develops a second peak due to the opening of the Nh-channel. Within both the Walecka and the chiral SU(3) models, it is observed that the ρ-meson spectral function has a strong dependence on the nucleon-ρ meson tensor coupling.

KAON CONDENSATION AND THE NUCLEAR EQUATION OF STATE

2011 ◽  
Vol 20 (supp02) ◽  
pp. 140-145
Author(s):  
ROSANA O. GOMES ◽  
DIMITER HADJIMICHEF ◽  
CÉSAR A. Z. VASCONCELLOS ◽  
ALEXANDRE MESQUITA ◽  
MOISÉS RAZEIRA ◽  
...  
Keyword(s):  
Phase Transition ◽  
Equation Of State ◽  
Degrees Of Freedom ◽  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Charge Neutrality ◽  
Nuclear Equation Of State ◽  
Kaon Condensation ◽  
The Mean

We study the effects of phase transition in the equation of state of a neutron star containing a condensate of anti-kaons, using an effective model with derivative couplings. In our formalism, nucleons interact through the exchange of σ, ω, ϱ, and δ meson fields in the presence of electrons and muons to accomplish electric charge neutrality and beta equilibrium. The phase transition to the anti-kaons condensate was implemented through the Gibbs conditions combined with the mean-field approximation, giving rise to a mixed phase of coexistence between hadron matter and the condensed of anti-kaons. In conclusion, we have found that isovector meson degrees of freedom contribute to tighten the Equation of State of Neutron Stars.

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