Effective interaction in non-degenerate model space

2011 ◽  
Vol 852 (1) ◽  
pp. 61-81 ◽  
Author(s):  
Kazuo Takayanagi
Keyword(s):  
Effective Interaction ◽  
Model Space ◽  
Degenerate Model

scholarly journals FORMAL RELATION AMONG VARIOUS HERMITIAN AND NON-HERMITIAN EFFECTIVE INTERACTIONS

2005 ◽  
Vol 14 (01) ◽  
pp. 21-28 ◽  
Author(s):  
RYOJI OKAMOTO ◽  
SHINICHIRO FUJII ◽  
KENJI SUZUKI
Keyword(s):  
Effective Interaction ◽  
Model Space ◽  
General Definition ◽  
Effective Interactions ◽  
Formal Relation ◽  
Definition Of ◽  
Effective Hamiltonians

A general definition of the model-space effective interaction is given. The energy-independent effective Hamiltonians derived in a time-independent way are classified systematically.

scholarly journals Shell-model calculations for upper pf-shell nuclei with an effective interaction

2018 ◽  
Vol 194 ◽  
pp. 01006
Author(s):  
Kalin Drumev
Keyword(s):  
Shell Model ◽  
Effective Interaction ◽  
Model Space ◽  
Model Calculations ◽  
Energy Eigenstates ◽  
Mixed Symmetry ◽  
Symmetry Approach ◽  
Oscillator Shell ◽  
Single Oscillator ◽  
Pf Shell

Results obtained for the energy spectra and the low-lying positive-parity energy eigenstates of the upper p f -shell nuclei 64Ge and 68Se with the use of the effective interaction JUN45 are reported. We address the question of how appropriate is the possibility to construct a symmetry-adapted shell model in a single oscillator shell using a Pairing-plus-Quadrupole Hamiltonian. Specifically, we study the goodness of the symmetries pseudo SU(3) and O(6) in the structure of the energy eigenstates. Finally, we relate our results to a proposed mixed-symmetry approach which is able to simultaneously account for the presence of both the pairing and the quadrupole modes as the most important ingredients in the effective interaction while using a restricted part of the full model space.

scholarly journals Shell model and Hartree-Fock calculations of electron scattering form factors for 25Mg nucleus

2019 ◽  
Vol 14 (31) ◽  
pp. 28-36
Author(s):  
Ali A. Alzubadi
Keyword(s):  
Shell Model ◽  
Electron Scattering ◽  
Single Particle ◽  
Effective Interaction ◽  
Form Factors ◽  
Model Space ◽  
Inelastic Electron ◽  
Hartree Fock ◽  
Particle Potential ◽  
Single Particle Potential

Shell model and Hartree-Fock calculations have been adopted to study the elastic and inelastic electron scattering form factors for 25Mg nucleus. The wave functions for this nucleus have been utilized from the shell model using USDA two-body effective interaction for this nucleus with the sd shell model space. On the other hand, the SkXcsb Skyrme parameterization has been used within the Hartree-Fock method to get the single-particle potential which is used to calculate the single-particle matrix elements. The calculated form factors have been compared with available experimental data.

scholarly journals Shell model calculations in the A=80-100 mass region and study of double β transitions

2020 ◽  
Vol 1 ◽  
pp. 156
Author(s):  
J. Sinatkas ◽  
L. D. Skouras ◽  
D. Strottman ◽  
J. D. Vergados
Keyword(s):  
Shell Model ◽  
Satisfactory Agreement ◽  
Effective Interaction ◽  
Model Space ◽  
Mass Region ◽  
Least Square ◽  
Matrix Elements ◽  
Model Calculations ◽  
Least Square Fit ◽  
The One

The structure of the Ζ,Ν < 50 nuclei is examined in a model space consisting of the 0g9/2, 1p1/2, 1p3/2 and the 0f5/2 hole orbitals outside the doubly closed 100Sn core. The effective interaction for this model space is derived by introducing second order corrections to the Sussex matrix elements, while the one-hole energies are deduced by a least square fit to the observed levels. The results of the calculation are found to be in very satisfactory agreement with experiment for all nuclei with 38<Ζ<46 but for Ζ<38 this agreement begins to deteriorate. Such a feature possibly indicates the appearance of deformation and the breaking of the Ν=50 core. The wavefunctions of the calculation are used to determine double β matrix elements in the Ge, Se, Sr and Kr isotopes.

scholarly journals Inelastic Form Factor Calculations for 46,48,50Ti Isotopes Using Tassie Model

2021 ◽  
Vol 2021 ◽  
pp. 1-4
Author(s):  
Mohanad H. Oleiwi
Keyword(s):  
Experimental Data ◽  
Wave Function ◽  
Momentum Transfer ◽  
Good Description ◽  
Effective Interaction ◽  
Form Factors ◽  
Model Space ◽  
Single Particle Wave Function ◽  
Particle Wave Function ◽  
Theoretical Results

Inelastic form factors of electrical transition have been calculated for 46,48,50Ti isotopes using the Tassie model. The form factors have been calculated for different exciting energies. The harmonic oscillator (HO) wave function has been used as a single-particle wave function. The model space has been considered as 1f7/2, 2p3/2, 2p1/2, and 2f5/2. Gx1 has been used as effective interaction in all calculations. In all calculations, the effective charge has been considered as 1.5e for proton and 0.5e for neutron. All obtained results have been compared with data from an experiment. The calculations show the Tassie model gives a good description of longitudinal form factors of 46,48,50Ti isotopes in E(2+) transitions as compared with experimental data, especially in the region below 2 fm−1 of momentum transfer, but in the E(4+), the theoretical results deviated slightly from experimental data especially in the region greater than 1.5 fm−1 of momentum transfer.

Summation of time-dependent folded diagrams for effective interactions with a non-degenerate model space

1995 ◽  
Vol 582 (1-2) ◽  
pp. 205-222 ◽  
Author(s):  
T.T.S. Kuo ◽  
F. Krmpotić ◽  
K. Suzuki ◽  
R. Okamoto
Keyword(s):  
Model Space ◽  
Time Dependent ◽  
Effective Interactions ◽  
Degenerate Model

scholarly journals Core-polarization effect in longitudinal electron scattering form factors of 65Cu nucleus

2019 ◽  
Vol 14 (31) ◽  
pp. 13-27
Author(s):  
Adie D. Salman
Keyword(s):  
Experimental Data ◽  
Shell Model ◽  
Electron Scattering ◽  
Transition Probabilities ◽  
Effective Interaction ◽  
Form Factors ◽  
Model Space ◽  
Inelastic Electron ◽  
Core Polarization ◽  
Reduced Transition Probabilities

Inelastic longitudinal electron scattering form factors to 2+ and 4+ states in 65Cu nucleus has been calculated in the (2p3/2 1f 5/2 2p1/2) shell model space with the F5PVH effective interaction. The harmonic oscillator potential has been applied to calculate the wave functions of radial single-particle matrix elements. Two shell model codes, CP and NUSHELL are used to obtain results. The form factor of inelastic electron scattering to 1/21−, 1/22−, 3/22−, 3/23−, 5/21−, 5/22− and 7/2- states and finding the transition probabilities B (C2) (in units of e2 fm4) for these transitions and B (C4) (in units of e2 fm8) for the transition 7/2-, and comparing them with experimental data. Both the form factors and reduced transition probabilities with core-polarization effects gave a reasonable description of the experimental data.

scholarly journals Deformed Hartree-Fock calculations for semileptonic processes in nuclei

2019 ◽  
Vol 11 ◽  
Author(s):  
T. S. Kosmas
Keyword(s):  
Single Particle ◽  
Good Description ◽  
Effective Interaction ◽  
Random Phase ◽  
Model Space ◽  
Spectroscopic Properties ◽  
Particle Spectrum ◽  
Hartree Fock ◽  
Nuclear Systems ◽  
Nuclear Processes

In nuclear structure calculations, the Deformed Hartree-Fock (DHF) provides generally a good description for the low-lying spectroscopic properties of odd-even, odd-odd and even-even nuclear systems of which the consideration of the deformation is motivated by many reasons. The common random phase approximations (RPA, QRPA, etc.) mostly used to accurately evaluate the transition matrix elements in many nuclear processes [1,2], are appropriate for only spherical even-even nuclear systems even though, sometimes, isotopes considered as rather deformed are studied. In the present work, we discuss the treatment within the DHF method of nuclei in the region A = 70 — 80. This region includes isotopes (like 72Ge, 76Ge, 72Se, etc) interesting for studying many nuclear processes as the ,0/3-decay, scattering of dark matter candidates off nuclei, μ~ —> e± conversions in nuclei. In our calculations the model space comprises 1P3/2, 0f5/2, 1pi/2 and 0p9/2 single particle Orbitals assuming 56Ni to be the inert core. The effective interaction employed, has been quite successfully used previously to describe many important features of the nuclei in this region. The lowest prolate Hartree-Fock single particle spectrum of some isotopes (72Ge, 76Ge) has been used to test the good angular momentum states which in this method are projected out from the intrinsic HF states. As an application, we examine the predictions of DHF for the exotic (μ~,ε~) conversion process. The contributions of all basic μ~ —> e~ operators originating from a general effective Lagrangian [2] are compared with those of normal QRPA methods obtained previously.

scholarly journals Shell Model Calculations for Some Properties of 29-34Mg Isotopes

2021 ◽  
pp. 1901-1911
Author(s):  
Lubna Abduljabbar Mahmood ◽  
Ghaith Naima Flaiyh
Keyword(s):  
Shell Model ◽  
Transition Probability ◽  
Effective Interaction ◽  
Model Space ◽  
High Energy ◽  
Neutron Separation Energy ◽  
Separation Energy ◽  
Model Calculations ◽  
Model Code ◽  
Single Neutron

The calculations of the shell model, based on the large basis, were carried out for studying the nuclear 29-34Mg structure. Binding energy, single neutron separation energy, neutron shell gap, two neutron separation energy, and reduced transition probability, are explained with the consideration of the contributions of the high-energy configurations beyond the model space of sd-shell. The wave functions for these nuclei are used from the model of the shell with the use of the USDA 2-body effective interaction. The OBDM elements are computed with the use of NuShellX@MSU shell model code that utilizes the formalism of proton-neutron.

scholarly journals The effect of short range correlation on the inelastic C2 and C4 form factors of 18O nucleus

2019 ◽  
Vol 14 (31) ◽  
pp. 37-50
Author(s):  
Abdullah S. Mdekil
Keyword(s):  
Charge Density ◽  
Short Range ◽  
Effective Interaction ◽  
Form Factors ◽  
Model Space ◽  
Charge Densities ◽  
Oscillator Wave Function ◽  
Inert Core ◽  
Harmonic Oscillator Wave Function ◽  
Short Range Correlations

The effect of short range correlations on the inelastic Coulomb form factors for excited +2 states (1.982, 3.919, 5.250 and 8.210MeV) and +4 states (3.553, 7.114, 8.960 and 10.310 MeV) in O18 is analyzed. This effect (which depends on the correlation parameterβ) is inserted into the ground state charge density distribution through the Jastrow type correlation function. The single particle harmonic oscillator wave function is used with an oscillator size parameter .b The parameters β and b are adjusted for each excited state separately so as to reproduce the experimental root mean square charge radius of .18O The nucleusO18 is considered as an inert core of C12 with two protons and four neutrons distributed over 212521211sdp−− active orbits. The total transition charge density comes from both the model space and core polarization transition charge densities. The realistic effective interaction of Reehal–Wildenthal (REWIL) is used for this model space. It is found that the introduction of the effect of short range correlations is necessary for obtaining a remarkable improvement for the calculated inelastic Coulomb form factors and considered as an essential for explanation the data amazingly throughout the whole range of considered momentum transfer.

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