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.

Self-consistent approximations for field theories at finite temperature

1993 ◽  
Vol 71 (5-6) ◽  
pp. 285-294
Author(s):  
M. H. Thoma
Keyword(s):  
Finite Temperature ◽  
Mean Field ◽  
Field Approximation ◽  
Two Dimensions ◽  
Mean Field Approximation ◽  
Coupling Constant ◽  
Starting Point ◽  
Consistent Approximations ◽  
The Mean ◽  
Mean Field Approximations

Various mean field approximations at finite temperature are used for calculating ground state energies and propagators of the [Formula: see text] theory in two dimensions and quantum chromodynamics (QCD). In the case of the [Formula: see text] theory a symmetry restoration is observed above a critical coupling constant if a temperature independent renormalization is used. In the case of QCD the mean field approximation is insufficient but can be regarded as a starting point for more complicated approximations, which are discussed qualitatively.

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 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.

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.

GREEN FUNCTIONS IN t-J MODEL OF HIGH-Tc SUPERCONDUCTIVITY

1994 ◽  
Vol 08 (22) ◽  
pp. 3137-3155 ◽  
Author(s):  
VAN HIEU NGUYEN
Keyword(s):  
Real Time ◽  
Finite Temperature ◽  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Green Functions ◽  
Imaginary Time ◽  
High Tc ◽  
High Tc Superconductivity ◽  
The Mean

The explicit expressions of the imaginary time normal and anomalous two–point Green functions in the t-J model of high-T c superconductivity without the single occupation constraint as well as those of the real time ones at a finite temperature are derived in the mean field approximation. The possible applications of these results are outlined.

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