Influence of left-right asymmetry degrees of freedom in self-consistent calculations of 20Ne

1983 ◽  
Vol 410 (1) ◽  
pp. 125-136 ◽  
Author(s):  
S. Marcos ◽  
H. Flocard ◽  
P.H. Heenen
Keyword(s):  
Degrees Of Freedom ◽  
Self Consistent ◽  
Left Right Asymmetry

QUANTUM CORRECTIONS TO THE CRANKING MODEL

1992 ◽  
Vol 01 (01) ◽  
pp. 95-130 ◽  
Author(s):  
ABRAHAM KLEIN ◽  
NIELS R. WALET ◽  
G. DO DANG
Keyword(s):  
Degrees Of Freedom ◽  
Quantum Correction ◽  
Mean Field ◽  
Original System ◽  
Quantum Corrections ◽  
Transition Rates ◽  
Rotation Symmetry ◽  
Exchange Effects ◽  
Self Consistent ◽  
The Mean

A method is described for the restoration of translation or rotation symmetry to a system of fermions, starting from a self-consistent cranking solution and valid when either momentum or angular momentum is large enough so that semi-classical approximations are valid. The quantum fluctuations that restore the broken symmetry are described in terms of the particle-hole degrees of freedom of the original system rather than by mapping these variables onto a boson space, as in most previous work. Only the leading quantum correction to the mean field solution is worked out in detail. New results include the treatment of direct and exchange effects on an equal footing and a method for computing transition rates.

scholarly journals Phase mixing importance for both Landau instability and damping

2017 ◽  
Vol 83 (1) ◽  
Author(s):  
D. D. A. Santos ◽  
Yves Elskens
Keyword(s):  
Numerical Calculation ◽  
Degrees Of Freedom ◽  
Hamiltonian Formalism ◽  
Langmuir Wave ◽  
The Self ◽  
Phase Mixing ◽  
Mixing Effect ◽  
Self Consistent ◽  
Landau Instability

We discuss the self-consistent dynamics of plasmas by means of a Hamiltonian formalism for a system of $N$ near-resonant electrons interacting with a single Langmuir wave. The connection with the Vlasov description is revisited through the numerical calculation of the van Kampen-like eigenfrequencies of the linearized dynamics for many degrees of freedom. Both the exponential-like growth as well as damping of the Langmuir wave are shown to emerge from a phase mixing effect among beam modes, revealing unexpected similarities between the stable and unstable regimes.

MICROSCOPIC SELF-CONSISTENT AND COLLECTIVE MODEL DESCRIPTION OF LOW-ENERGY NUCLEAR STRUCTURE

1989 ◽  
Vol 04 (09) ◽  
pp. 2063-2146 ◽  
Author(s):  
K. HEYDE
Keyword(s):  
Nuclear Structure ◽  
Degrees Of Freedom ◽  
Collective Motion ◽  
Collective Model ◽  
Model Description ◽  
Mixed Symmetry ◽  
Self Consistent ◽  
Closed Shells ◽  
Model Approach

In the present review, an attempt is made to approach the different facets of the nucleus at low excitation energy from both a microscopic, self-consistent and a collective model approach. Some attention is given on how to relate the two “opposite” approaches to nuclear structure. In a final chapter, we discuss some newly appreciated modes in the nucleus that are specific to the proton and neutron degrees of freedom e.g. the study of intruder states near closed shells and the presence of proton-neutron mixed-symmetry collective motion.

THE DESCRIPTION AND ROLE OF FLUCTUATIONS IN COLLECTIVE DEGREES OF FREEDOM IN MODELS OF NUCLEAR STRUCTURE BASED ON THE SELF-CONSISTENT MEAN FIELD

2010 ◽  
Vol 25 (21n23) ◽  
pp. 1787-1791
Author(s):  
MICHAEL BENDER ◽  
PAUL-HENRI HEENEN
Keyword(s):  
Nuclear Structure ◽  
Density Functional ◽  
Degrees Of Freedom ◽  
Density Functional Method ◽  
Mean Field ◽  
Functional Method ◽  
Energy Density Functional ◽  
Open Questions ◽  
Self Consistent

This contribution sketches recent efforts to explicitly include fluctuations in collective degrees of freedom into a universal energy density functional method for nuclear structure, their successes, and some remaining open questions.

ASYMPTOTIC BEHAVIOUR OF THE VACUUM ENERGY FOR SMALL SKYRMIONS

1990 ◽  
Vol 05 (18) ◽  
pp. 3549-3597 ◽  
Author(s):  
JOSEF A. ZUK
Keyword(s):  
Field Theory ◽  
Asymptotic Behaviour ◽  
Degrees Of Freedom ◽  
Vacuum Energy ◽  
Functional Dependence ◽  
Analytical Approximation ◽  
Low Energy ◽  
Fermion Fields ◽  
Self Consistent ◽  
Vacuum Instability

Various schemes for deriving effective Lagrangians, involving both quark and meson degrees of freedom, which are intermediate between QCD and low-energy pion dynamics have been proposed. While integration over the fermion fields within the framework of renormalized field theory leads to a vacuum instability, physically reasonable results are obtained for the theory taken with finite cut-off. In principle, properties of the nucleon, such as its mass, can be obtained from a self-consistent calculation in the Skyrmion sector. This procedure can be simplified by implementing an analytical approximation for the fermion vacuum energy which plays a central role. We discuss such an approximation, and use it to calculate exactly the asymptotic behaviour of the vacuum energy for small Skyrmions. It is found that, unlike in the renormalized theory, its functional dependence on the Skymion radius in this limit depends on the characteristics of the Skyrmion profile and choice of regularization scheme; however, the cut-off field theory exhibits no vacuum instability.

scholarly journals PHASE STRING THEORY FOR DOPED ANTIFERROMAGNETS

2007 ◽  
Vol 21 (06) ◽  
pp. 773-827 ◽  
Author(s):  
ZHENG-YU WENG
Keyword(s):  
Phase Diagram ◽  
High Temperature ◽  
String Theory ◽  
Physical Properties ◽  
Degrees Of Freedom ◽  
The Self ◽  
The Novel ◽  
Self Consistent ◽  
Recent Developments ◽  
Global Phase Diagram

The recent developments of the phase string theory for doped antiferromagnets will be briefly reviewed. Such theory is built upon a singular phase string effect induced by the motion of holes in a doped antiferromagnet, which as a precise property of the t-J model dictates the novel competition between the charge and spin degrees of freedom. A global phase diagram including the antiferromagnetic, superconducting, lower and upper pseudogap, and high-temperature "normal" phases, as well as a series of anomalous physical properties of these phases will be presented as the self-consistent and systematic consequences of the phase string theory.

FISSION BARRIERS OF SUPERHEAVY NUCLEI IN THE SKYRME-HARTREE-FOCK MODEL

2006 ◽  
Vol 15 (02) ◽  
pp. 302-310 ◽  
Author(s):  
ANDRZEJ STASZCZAK ◽  
JACEK DOBACZEWSKI ◽  
WITOLD NAZAREWICZ
Keyword(s):  
Axial Symmetry ◽  
Degrees Of Freedom ◽  
Mean Field ◽  
Superheavy Nuclei ◽  
Reflection Symmetry ◽  
Pairing Force ◽  
Hartree Fock ◽  
Fission Barriers ◽  
Self Consistent

Constrained Skyrme-Hartree-Fock calculations of static fission barriers are performed for even-even elements with Z = 100÷110 as well as for superheavy N=184 isotones. In our study we use the Skyrme parametrization SLy4 and a seniority pairing force treated in the BCS approximation. The computations are carried out applying a code that makes it possible to break all self-consistent symmetries of the nuclear mean field, including axial symmetry and reflection symmetry. The influence of reflection-asymmetric and triaxial degrees of freedom on fission barriers are discussed.

scholarly journals ELECTROMAGNETIC DEFLECTION OF SPINNING PARTICLES

1994 ◽  
Vol 09 (03) ◽  
pp. 461-473 ◽  
Author(s):  
JOHN P. COSTELLA ◽  
BRUCE H.J. MCKELLAR
Keyword(s):  
Magnetic Dipole ◽  
Magnetic Dipole Moment ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Radiation Reaction ◽  
Exact Form ◽  
Dipole Force ◽  
Self Consistent ◽  
Recent Debate ◽  
The Subject

We show that it is possible to obtain self-consistent and physically acceptable relativistic classical equations of motion for a pointlike spin-half particle possessing an electric charge and a magnetic dipole moment, directly from a manifestly covariant Lagrangian, if the classical degrees of freedom are appropriately chosen. It is shown that the equations obtained encompass the well-tested Lorentz force and Thomas-Bargmann-Michel-Telegdi spin equations, as well as providing a definite specification of the classical magnetic dipole force, whose exact form has been the subject of recent debate. Radiation reaction — the force and torque on an accelerated particle due to its self-interaction — is neglected at this stage.

COLLECTIVE QUADRUPOLE EXCITATIONS WITHIN A SELF-CONSISTENT APPROACH

2006 ◽  
Vol 15 (02) ◽  
pp. 379-386 ◽  
Author(s):  
L. PRÓCHNIAK
Keyword(s):  
Experimental Data ◽  
Degrees Of Freedom ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Low Energy ◽  
Time Dependent ◽  
Collective Excitations ◽  
Skyrme Interaction ◽  
Self Consistent ◽  
Consistent Approach

Low energy quadrupole collective excitations are investigated using a model based on the Adiabatic Time Dependent HFB theory. Distinctive feature of proposed method is an extension of the collective space by adding variables referring to pairing degrees of freedom. In the microscopic part of the model effective Skyrme interaction and constant G pairing force are employed. Calculated energy levels and B(E2) transition probabilities in the 128 Xe nucleus are compared with the experimental data.

SKYRME–HARTREE–FOCK CALCULATIONS OF FISSION BARRIERS OF THE HEAVIEST AND SUPERHEAVY NUCLEI

2005 ◽  
Vol 14 (03) ◽  
pp. 395-402 ◽  
Author(s):  
ANDRZEJ STASZCZAK ◽  
JACEK DOBACZEWSKI ◽  
WITOLD NAZAREWICZ
Keyword(s):  
Degrees Of Freedom ◽  
Superheavy Nuclei ◽  
Pairing Force ◽  
Hartree Fock ◽  
Fission Barriers ◽  
Self Consistent

Self-consistent Skyrme–Hartree–Fock (SHF) calculations of static fission barriers are presented for even-even Fermium isotopes as well as for superheavy even-even N=184 isotones. In the particle-hole channel, we use the SLy4 Skyrme parametrization, while in the particle-particle channel we take a T=1 seniority pairing force treated in the BCS approximation. The influence of reflection-asymmetric and triaxial degrees of freedom on the static fission paths are investigated.

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