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.

CRANKING THE CHIRAL SOLITON BAG MODEL: QUANTUM CORRECTIONS

1988 ◽  
Vol 03 (13) ◽  
pp. 1285-1290 ◽  
Author(s):  
GÉRARD CLEMENT ◽  
JACQUELINE STERN
Keyword(s):  
Coherent State ◽  
Mean Field ◽  
Projection Methods ◽  
Quantum Corrections ◽  
Drastic Reduction ◽  
Bag Model ◽  
Chiral Soliton ◽  
The Mean

The generation of physical states from mean field hedgehogs by cranking is extended to coherent hedgehogs, thus improving the agreement between the cranking and coherent state projection methods, and enabling us to correct simultaneously for translational and rotational fluctuations. These corrections lead to a drastic reduction in the mean nucleon-delta mass which, for the physical values of mπ and Fπ, is lower than, or approximately equal to, the experimental value.

CURRENTS, SPIN DENSITIES AND MEAN-FIELD FORM FACTORS IN ROTATING NUCLEI: A SEMI-CLASSICAL APPROACH

2004 ◽  
Vol 13 (01) ◽  
pp. 225-233 ◽  
Author(s):  
J. BARTEL ◽  
K. BENCHEIKH ◽  
P. QUENTIN
Keyword(s):  
Mean Field ◽  
Form Factors ◽  
Spin Vector ◽  
Self Consistent ◽  
Field Form ◽  
Local Densities ◽  
The Mean ◽  
Self Consistency ◽  
Spin Densities ◽  
Rotating Nuclei

We present self-consistent semi-classical local densities characterising the structure of rotating nuclei. A particular emphasis is put on those densities which are generated by the breaking of time-reversal symmetry through the cranking piece of the Routhian, namely the current density and the spin vector density. Our approach which is based on the Extended-Thomas-Fermi method goes beyond the Inglis cranking approach and contains naturally the Thouless-Valatin self-consistency terms expressing the response of the mean field to the time-odd part of the density matrix.

scholarly journals BOSONIC CHERN-SIMONS FIELD THEORY OF ANYON SUPERCONDUCTIVITY

1992 ◽  
Vol 07 (28) ◽  
pp. 2627-2636
Author(s):  
NATHAN WEISS
Keyword(s):  
Field Theory ◽  
Particle Density ◽  
Equations Of Motion ◽  
Mean Field ◽  
Meissner Effect ◽  
Quantum Corrections ◽  
Simple Explanation ◽  
Field Solution ◽  
The Mean ◽  
Chern Simons

We study the quantum field theory of non-relativistic bosons coupled to a Chern-Simons gauge field at nonzero particle density. This field theory is relevant to the study of anyon superconductors in which the anyons are described as bosons with a statistical interaction. We show that it is possible to find a mean field solution to the equations of motion for this system which has some of the features of Bose condensation. The mean field solution consists of a lattice of vortices each carrying a single quantum of statistical magnetic flux. We speculate on the effects of the quantum corrections to this mean field solution. We argue that the mean field solution is only stable under quantum corrections if the Chern-Simons coefficient N=2πθ/g2 is an integer. Consequences for anyon superconductivity are presented. A simple explanation for the Meissner effect in this system is discussed.

NEUTRON–PROTON PAIRING CORRELATION FOR THE ROTATIONAL MOTION OF N = Z72Kr, 76Sr, AND 80Zr NUCLEI

2011 ◽  
Vol 20 (08) ◽  
pp. 1687-1699
Author(s):  
PRIANKA ROY ◽  
SHASHI K. DHIMAN
Keyword(s):  
Effective Interaction ◽  
Mean Field ◽  
High Spin State ◽  
Pairing Correlation ◽  
Effective Interactions ◽  
Hartree Fock ◽  
Self Consistent ◽  
The Mean ◽  
Proton Pairing ◽  
Band Crossing

The high-spin state properties of the neutron–proton (np) residual effective interaction are analyzed in N = Z72 Kr , 76 Sr , and 80 Zr nuclei. The self-consistent microscopic Hartree–Fock–Bogoliubov (HFB) equations have been solved by employing monopole corrected two-body effective interaction. A band crossing is observed in 72 Kr nucleus at J = 14ℏ state with monopole corrected "HPU1" and "HPU2" effective interactions. The VAP–HFB theory suggests that the "4p–4h" excitations by np residual interaction are the essential ingredients of the mean-field description of the occurence of backbending in 72 Kr nucleus.

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.

scholarly journals PAIRING CORRELATIONS BEYOND THE MEAN FIELD

2007 ◽  
Vol 16 (02) ◽  
pp. 222-236 ◽  
Author(s):  
M. BENDER ◽  
T. DUGUET
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Mean Field ◽  
Energy Functional ◽  
Functional Theory ◽  
Self Consistent ◽  
Configuration Mixing ◽  
Pairing Correlations ◽  
The Mean

We discuss dynamical pairing correlations in the context of configuration mixing of projected self-consistent mean-field states, and the origin of a divergence that might appear when such calculations are done using an energy functional in the spirit of a naive generalized density functional theory.

scholarly journals On the multiscale analysis of a two phase material: crystal plasticity versus mean field

2021 ◽  
Author(s):  
Shahrzad Mirhosseini ◽  
Semih Perdahcioglu ◽  
Eisso Atzema ◽  
Ton van den Boogaard
Keyword(s):  
Crystal Plasticity ◽  
Mean Field ◽  
Multiscale Methods ◽  
Material Behavior ◽  
Strain Partitioning ◽  
Two Phase ◽  
Self Consistent ◽  
Grain Orientations ◽  
The Mean ◽  
Two Phases

In this paper, a comparison is made between two multiscale methods, namely crystal plasticity finite element and mean field on a material composed of two phases. Both methods are used to homogenize a given microstructure. In order to obtain macroscopic behavior, in the mean field approach, a Self-Consistent scheme is used to evaluate stress and strain partitioning among the phases. In this method, an average of the fields is estimated and local distributions cannot be captured. In parallel, crystal plasticity simulations on Representative Volume Elements (RVEs) composed of hexagonal grains are performed. In these simulations, grain orientations are attributed randomly respecting Mackenzie's distribution function in order to achieve isotropic behavior and macroscopic hardening is extracted from the simulations. The results on macroscopic hardening of both methods are compared to distinguish the extents of validity of mean field homogenization. In addition to Self- Consistent, other mean field schemes such as Voigt, Reuss and Bound-Interpolation are compared in terms of efficiency and accuracy. The comparison manifests that Self-Consistent scheme is capable of predicting material behavior well.

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