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.

Study of High-spin States for 90,91,92Y Isotopes by Using Oxbash Code

2021 ◽  
Vol 14 (1) ◽  
pp. 25-33
Keyword(s):  
Experimental Data ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Model Space ◽  
Low Energy ◽  
Energy Spectra ◽  
Spin States ◽  
Nuclear Shell Model ◽  
High Spin States ◽  
Nuclear Shell

Abstract: In this paper, calculations of 90,91,92Y isotopes have been performed by application of nuclear shell model in the Gloeckner (Gl) model space for two different interactions (Gloeckner (Gl) and Gloeckner pulse bare G-Matrix (Glb) using Oxbash code. The energy levels are compared and discussed with experimental data and based on our results, many predictions about spins and parity were observed between experimental states, in addition to the predictions of low-energy spectra and B (E2; ↓) and B (M1; ↓)) transitional strengths in the isotopes 90,91,92Y. These predictions were not known in the experimental data. Keywords: Energy levels, Transition probabilities, Oxbash code.

scholarly journals COLLECTIVE EXCITATIONS OF TRANSACTINIDE NUCLEI IN A SELF-CONSISTENT MEAN FIELD THEORY

2008 ◽  
Vol 17 (01) ◽  
pp. 160-167 ◽  
Author(s):  
L. PRÓCHNIAK
Keyword(s):  
Field Theory ◽  
Experimental Data ◽  
Potential Energy ◽  
Reasonable Agreement ◽  
Transition Probabilities ◽  
Mean Field Theory ◽  
Mean Field ◽  
Collective Excitations ◽  
Self Consistent ◽  
Collective States

We applied the ATDHFB approach for study of properties of collective quadrupole states in several transactinide nuclei: 238 U , 240 Pu , 242 Pu , 246 Cm , 248 Cm , 250 Cf and 252 Cf . Calculated energies and B(E2) transition probabilities are in a reasonable agreement with experimental data. We present also results concerning superdeformed collective states in the second minimum of potential energy of the 240 Pu nucleus.

Variational Calculation of the Lower Vibrational Energy Levels of the Ammonia Molecule

1982 ◽  
Vol 37 (4) ◽  
pp. 398-400 ◽  
Author(s):  
Philippe Bopp ◽  
Don R. McLaughlin ◽  
Max Wolfsberg
Keyword(s):  
Experimental Data ◽  
Degrees Of Freedom ◽  
Vibrational Energy ◽  
Energy Levels ◽  
Variational Calculation ◽  
Ammonia Molecule ◽  
Inversion Barrier ◽  
Barrier Potential ◽  
Vibrational Energy Levels

Abstract A variational calculation of the lower-lying vibrational energy levels of the ammonia molecule is performed, in which all six vibrational degrees of freedom are treated simultaneously. A literature potential is assumed for all non-inversion motions; a new inversion barrier potential with a barrier of 1616 cm-1 is determined by fitting experimental data.

Calculation of the structure and transition probabilities of low energy levels of Fe+24 and Fe+25

1995 ◽  
Vol 19 (4) ◽  
pp. 495-506
Author(s):  
Hai-guang Xu ◽  
Shi-wei Zhang ◽  
Jun-feng Chen ◽  
Jun-han You
Keyword(s):  
Transition Probabilities ◽  
Energy Levels ◽  
Low Energy

scholarly journals ON THE STABILITY OF PERIODICALLY TIME-DEPENDENT QUANTUM SYSTEMS

2008 ◽  
Vol 20 (06) ◽  
pp. 725-764 ◽  
Author(s):  
P. DUCLOS ◽  
E. SOCCORSI ◽  
P. ŠŤOVÍČEK ◽  
M. VITTOT
Keyword(s):  
Transition Probabilities ◽  
Initial Conditions ◽  
Energy Levels ◽  
Sufficient Conditions ◽  
Energy Operator ◽  
Mean Value ◽  
Quantum Systems ◽  
Time Dependent ◽  
Dense Subspace ◽  
Periodically Driven

The main motivation of this article is to derive sufficient conditions for dynamical stability of periodically driven quantum systems described by a Hamiltonian H(t), i.e. conditions under which it holds true sup t ∈ ℝ|〈ψt, H(t)ψt〉| < ∞ where ψt denotes a trajectory at time t of the quantum system under consideration. We start from an analysis of the domain of the quasi-energy operator. Next, we show, under certain assumptions, that if the spectrum of the monodromy (Floquet) operator U(T, 0) is pure point then there exists a dense subspace of initial conditions for which the mean value of the energy is uniformly bounded in the course of time. Further, we show that if the propagator admits a differentiable Floquet decomposition then ‖H(t)ψt‖ is bounded in time for any initial condition ψ0, and one employs the quantum KAM algorithm to prove the existence of this type of decomposition for a fairly large class of H(t). In addition, we derive bounds uniform in time on transition probabilities between different energy levels, and we also propose an extension of this approach to the case of a higher order of differentiability of the Floquet decomposition. The procedure is demonstrated on a solvable example of the periodically time-dependent harmonic oscillator.

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.

Investigation of isospin excited and mixed-symmetry states in even–even N = Z nuclei

2018 ◽  
Vol 27 (08) ◽  
pp. 1850065 ◽  
Author(s):  
Falih H. Al-Khudair
Keyword(s):  
Excited States ◽  
Degrees Of Freedom ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Dynamical Symmetry ◽  
Systematic Investigation ◽  
Wave Functions ◽  
Mixed Symmetry ◽  
Mixed Symmetry States ◽  
Boson Model

Mixed-symmetry and isospin excited states are typical of the interacting boson model with isospin (IBM-3). With a view to look for such states, levels scheme of the IBM-3 dynamical symmetry is discussed. A systematic investigation in the proton and neutron degrees of freedom of the energy levels has been carried out. A sequence of isospin excitation bands has been identified. We have analyzed the wave functions and given the symmetrical labeling of the states. The transition probabilities between the isospin excitation states of model limits are analyzed in terms of isoscalar and isovector decompositions. The present calculations suggest that a combination of isospin excitation and mixed-symmetry states can provide substantial information on the structure of nuclear states. Calculations for [Formula: see text] and [Formula: see text] nuclei are presented and compared with the results of the shell model and available experimental data.

Application of Visco-Plastic Self Consistent Approach to Model Deformation Characteristics of Magnesium with Different Textures

2011 ◽  
Vol 702-703 ◽  
pp. 80-84
Author(s):  
Apu Sarkar ◽  
J.K. Chakravartty
Keyword(s):  
Experimental Data ◽  
Experimental Evidence ◽  
Uniaxial Tensile ◽  
Deformation Characteristics ◽  
Self Consistent ◽  
Plastic Forming ◽  
Constitutive Response ◽  
Low Symmetry ◽  
Consistent Approach ◽  
Good Agreement

The viscoplastic self-consistent (VPSC) formulation is by now a well established approach for simulating texture development and constitutive response during plastic forming of high and low-symmetry polycrystals. In this work we have used the VPSC approach to model the uniaxial tensile and compressive deformation characteristics of pure magnesium with random and extruded texture. We compare our results with experimental data and find that they are in good agreement with the available experimental evidence.

COLLECTIVE PAIRING HAMILTONIAN IN A SELF-CONSISTENT APPROACH

2007 ◽  
Vol 16 (02) ◽  
pp. 352-359 ◽  
Author(s):  
L. PRÓCHNIAK
Keyword(s):  
Potential Energy ◽  
Ground State ◽  
Mean Field ◽  
Pairing Interaction ◽  
Skyrme Interaction ◽  
State Dependent ◽  
Self Consistent ◽  
Collective Hamiltonian ◽  
Consistent Approach

We present general results for mass parameters and a collective potential energy obtained by ATDHFB and GCM+GOA methods for a state dependent pairing interaction. We apply the ATDHFB method in the case of mean-field calculations with Skyrme interaction for the 128 Xe nucleus. Dependence of the collective Hamiltonian and its ground state on the strength of the δ pairing interaction is discussed.

THE RELATIVISTIC MEAN FIELD THEORY AND LOW ENERGY QUADRUPOLE COLLECTIVE EXCITATIONS

2004 ◽  
Vol 13 (01) ◽  
pp. 217-224 ◽  
Author(s):  
L. PRÓCHNIAK ◽  
P. RING
Keyword(s):  
Field Theory ◽  
Experimental Data ◽  
Single Particle ◽  
Mean Field Theory ◽  
Mean Field ◽  
Low Energy ◽  
Collective Excitations ◽  
Relativistic Mean Field ◽  
Calculated Mass ◽  
Theoretical Results

We present an attempt to describe low lying quadrupole collective excitations within the frame of the RMF theory. Single particle wavefunctions obtained from the RMF are used to calculate mass parameters in the cranking approximation of the ATDHFB. The general Bohr hamiltonian with the calculated mass parameters yields collective energies and wavefunctions. Theoretical results are compared with the experimental data in the case of the γ soft 110 Ru and 126 Ba nuclei.

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