Calculations of Gamow–Teller Transition Strengths in fp-Shell Nuclei Using Shell Model

2020 ◽  
pp. 1-5
Author(s):  
Fouad A. Majeed ◽  
Sarah M. Obaid
Keyword(s):  
Shell Model ◽  
Theoretical Calculations ◽  
Model Space ◽  
Exchange Reactions ◽  
Model Calculations ◽  
Effective Interactions ◽  
Mechanisms Of Formation ◽  
Nuclear Structures ◽  
The Individual ◽  
Gamow Teller

The Gamow–Teller (GT) strength transitions in nuclear structures and astrophysical processes proved to be very important to understand the mechanisms of formation of neutron stars and black holes, therefore the GT transitions in the 46Ti→46V, 47Ti→47V, 48Ti→48V, and 50Cr→50Mn charge-exchange reactions have been studied. The shell model calculations have been carried out in the fp-model space without any restrictions using the GXFP1A, KB3G, and FPD6 effective interactions. The calculation of the GT distribution is compared with recent available experimental data. The theoretical calculations are in reasonably good agreement with the experimental GT distributions and with the summed transition strengths B(GT). For the individual transformations we have reached a qualitative agreement, while the measured cumulative transformation strengths are closely matched by the observed ones.

scholarly journals Gamow-Teller strengths of some sd-shell nuclei in the shell model framework

2020 ◽  
Vol 66 (3 May-Jun) ◽  
pp. 330 ◽  
Author(s):  
S. M. Obaid ◽  
H. M. Tawfeek
Keyword(s):  
Shell Model ◽  
Model Space ◽  
Transition Strength ◽  
Model Framework ◽  
Model Calculations ◽  
Effective Interactions ◽  
Calculated Distribution ◽  
Gamow Teller ◽  
Sd Model ◽  
Strength Distributions

The nuclear Gamow-Teller (GT) transition strength distributions B(GT)have been studied for some sd-shell nuclei in the (3He, t) charge-exchangereactions. The shell model calculations were performed by employing theUSDA and USDB effective interactions in the sd-model space. The results of B(GT) calculations reproduce the the experimental Gamow-Tellerstrength distributions well, while the calculated distribution of summedGT transition strengths were closely reproduce the observed ones.

scholarly journals Study of the Electric Quadrupole Moments for some Scandium Isotopes Using Shell Model Calculations with Different Interactions

2018 ◽  
Vol 15 (3) ◽  
pp. 304-309
Author(s):  
Baghdad Science Journal
Keyword(s):  
Shell Model ◽  
Theoretical Calculations ◽  
Microscopic Theory ◽  
Model Space ◽  
Electric Quadrupole ◽  
Quadrupole Moments ◽  
Core Polarization ◽  
Model Calculations ◽  
Major Shell ◽  
Experimental Values

The electric quadrupole moments for some scandium isotopes (41, 43, 44, 45, 46, 47Sc) have been calculated using the shell model in the proton-neutron formalism. Excitations out of major shell model space were taken into account through a microscopic theory which is called core polarization effectives. The set of effective charges adopted in the theoretical calculations emerging about the core polarization effect. NushellX@MSU code was used to calculate one body density matrix (OBDM). The simple harmonic oscillator potential has been used to generate the single particle matrix elements. Our theoretical calculations for the quadrupole moments used the two types of effective interactions to obtain the best interaction compared with the experimental data. The theoretical results of the quadrupole moments for some scandium isotopes performed with FPD6 interaction and Bohr-Mottelson effective charge agree with experimental values.

scholarly journals High-spin structures of 77,79,81,83As isotopes

2015 ◽  
Vol 30 (19) ◽  
pp. 1550093 ◽  
Author(s):  
Vikas Kumar ◽  
P. C. Srivastava ◽  
Irving O. Morales
Keyword(s):  
Shell Model ◽  
Magnetic Moments ◽  
Energy Levels ◽  
Model Space ◽  
Theoretical Development ◽  
Model Calculations ◽  
Effective Interactions ◽  
Spin Structures ◽  
Neutron Pair ◽  
Good Agreement

In this paper, we report comprehensive set of shell model calculations for arsenic isotopes. We performed shell model calculations with two recent effective interactions JUN45 and jj44b. The overall results for the energy levels and magnetic moments are in rather good agreement with the available experimental data. We have also reported competition of proton- and neutron-pair breakings analysis to identify which nucleon pairs are broken to obtain the total angular momentum of the calculated states. Further theoretical development is needed by enlarging model space by including [Formula: see text] and [Formula: see text] orbitals.

scholarly journals Large Scale Shell Model Calculations of the Negative-Parity States Structure in 24Mg Nucleus

2021 ◽  
Vol 66 (4) ◽  
pp. 293
Author(s):  
A.A. Al-Sammarraie ◽  
F.A. Ahmed ◽  
A.A. Okhunov
Keyword(s):  
Shell Model ◽  
Large Scale ◽  
Transition Probabilities ◽  
Transition Probability ◽  
Energy Levels ◽  
Form Factors ◽  
Model Space ◽  
Negative Parity ◽  
Matrix Elements ◽  
Model Calculations

The negative-parity states of 24Mg nucleus are investigated within the shell model. We are based on the calculations of energy levels, total squared form factors, and transition probability using the p-sd-pf (PSDPF) Hamiltonian in a large model space (0 + 1) hW. The comparison between the experimental and theoretical states showed a good agreement within a truncated model space. The PSDPF-based calculations successfully reproduced the data on the total squared form factors and transition probabilities of the negative-parity states in 24Mg nucleus. These quantities depend on the one-body density matrix elements that are obtained from the PSDPF Hamiltonian. The wave functions of radial one-particle matrix elements calculated with the harmonic-oscillator potential are suitable to predict experimental data by changing the center-of-mass corrections.

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 DESCRIPTION OF 102–108Sn ISOTOPES

2012 ◽  
Vol 21 (04) ◽  
pp. 1250049
Author(s):  
T. TRIVEDI ◽  
P. C. SRIVASTAVA ◽  
D. NEGI ◽  
I. MEHROTRA
Keyword(s):  
Shell Model ◽  
Single Particle ◽  
State Of The Art ◽  
Model Space ◽  
Model Description ◽  
Nuclear Shell Model ◽  
Model Calculations ◽  
Particle Orbits ◽  
Recent Experimental Work ◽  
Nuclear Shell

We have performed shell model calculations for neutron deficient even 102-108 Sn and odd 103-107 Sn isotopes in sdg7/2h11/2 model space using two different interactions. The first set of interaction is due to Brown et al. and second is due to Hoska et al. The calculations have been performed using doubly magic 100 Sn as core and valence neutrons are distributed over the single particle orbits 1g7/2, 2d5/2, 2d3/2, 3s1/2 and 1h11/2. In more recent experimental work for 101 Sn [I. G. Darby et al., Phys. Rev. Lett.105 (2010) 162502], the g.s. is predicted as 5/2+ with excited 7/2+ at 172 keV. We have also performed another two set of calculations by taking difference in single particle energies of 2d5/2 and 1g7/2 orbitals by 172 keV. The present state-of-the-art shell model calculations predict fair agreement with the experimental data. These calculations serve as a test of nuclear shell model in the region far from stability for unstable Sn isotopes near the doubly magic 100 Sn core.

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