scholarly journals Energy spectra and E2 transition rates of 124—130Ba

2016 ◽  
Vol 25 (10) ◽  
pp. 1650086 ◽  
Author(s):  
H. Sabri ◽  
M. Seidi
Keyword(s):  
Energy Spectra ◽  
Interacting Boson Model ◽  
Transition Rates ◽  
Control Parameters ◽  
Isotopic Chain ◽  
Theoretical Predictions ◽  
Phase Transition Region ◽  
Boson Model ◽  
Energy Surfaces ◽  
Shape Phase Transition

In this paper, we have studied the energy spectra and [Formula: see text] values of [Formula: see text]Ba isotopes in the shape phase transition region between the spherical and gamma unstable deformed shapes. We have used a transitional interacting Boson model (IBM), Hamiltonian which is based on affine SU(1,1) Lie algebra in the both IBM-1 and 2 versions and also the Catastrophe theory in combination with a coherent state formalism to generate energy surfaces and determine the exact values of control parameters. Our results for control parameters suggest a combination of [Formula: see text](5) and SO(6) dynamical symmetries in this isotopic chain. Also, the theoretical predictions can be rather well reproduce the experimental counterparts, when the control parameter is approached to the SO(6) limit.

scholarly journals Mixed Symmetry States in 92Zr and 94Mo Nuclei

2021 ◽  
Vol 66 (12) ◽  
pp. 1013
Author(s):  
S.N. Abood ◽  
A.A. Al-Rawi ◽  
L.A. Najam ◽  
F.M. Al-Jomaily
Keyword(s):  
Experimental Data ◽  
Energy Spectra ◽  
Interacting Boson Model ◽  
Transition Rates ◽  
Collective Models ◽  
Electromagnetic Transition ◽  
Mixed Symmetry ◽  
Mixed Symmetry States ◽  
Boson Model ◽  
Phonon Model

Mixed-symmetry states of 92Zr and 94Mo isotopes are investigated with the use of the collective models, Interacting Boson Model-2 (IBM-2) and Quasiparticle Phonon Model (QPM). The energy spectra and electromagnetic transition rates for these isotopes are calculated. The results of IBM-2 and QPM are compared with available experimental data. We have obtained a satisfactory agreement, and IBM-2 gives a better description. In these isotopes, we observe a few states having a mixed symmetry such as 2+2, 2+3, 3+1, and 1+s. It is found that these isotopes have a vibrational shape corresponding to the U(5) symmetry.

A theoretical study of energy spectra and transition probabilities of 200–204Hg isotopes in transitional region of IBM

2014 ◽  
Vol 23 (10) ◽  
pp. 1450056 ◽  
Author(s):  
H. Sabri
Keyword(s):  
Experimental Data ◽  
Theoretical Study ◽  
Transition Probabilities ◽  
Energy Spectra ◽  
Interacting Boson Model ◽  
Transitional Region ◽  
Transition Rates ◽  
Scale Factors ◽  
Boson Model ◽  
Good Agreement

In this paper, by using the SO(6) representation of eigenstates and transitional Interacting Boson Model (IBM) Hamiltonian, the evolution from prolate to oblate shapes along the chain of Hg isotopes is studied. Parameter-free (up to overall scale factors) predictions for spectra and B(E2) transition rates are found to be in good agreement with experimental data for 200–204 Hg isotopes which are supported to be located in this transitional region.

scholarly journals Connecting the X(5)-β2, X(5)-β4, and X(3) models to the shape/phase transition region of the Interacting Boson Model

2020 ◽  
Vol 15 ◽  
pp. 118
Author(s):  
E. A. McCutchan ◽  
D. Bonatsos ◽  
R. F. Casten
Keyword(s):  
Phase Transition ◽  
Transition Region ◽  
Interacting Boson Model ◽  
Shape Transition ◽  
Scale Factors ◽  
Phase Transition Region ◽  
Boson Model ◽  
Shape Phase Transition ◽  
Two Parameter ◽  
Boson Approximation

The parameter independent (up to overall scale factors) predictions of the X(5)-β2, X(5)-β4, and X(3) models, which are variants of the X(5) critical point symmetry developed within the framework of the geometric collective model, are compared to two- parameter calculations in the framework of the interacting boson approximation (IBA) model. The results show that these geometric models coincide with IBA parameters consistent with the phase/shape transition region of the IBA for boson numbers of physical interest (close to 10). 186Pt and 172Os are identified as good examples of X(3), while 146Ce, 174Os and 158Er, 176Os are identified as good examples of X(5)-β2 and X(5)-β4 behavior respectively.

Isospin excitation and shape phase transition in odd-mass Cu isotopes

2017 ◽  
Vol 26 (06) ◽  
pp. 1750036 ◽  
Author(s):  
M. Ghapanvari ◽  
M. A. Jafarizadeh ◽  
N. Fouladi ◽  
Z. Ranjbar ◽  
N. Amiri
Keyword(s):  
Phase Transition ◽  
Transition Probabilities ◽  
Closed Shell ◽  
Energy Spectra ◽  
Control Parameters ◽  
Fermion Model ◽  
Cu Isotopes ◽  
Phase Transition Region ◽  
Shape Phase Transition ◽  
Good Agreement

In this paper, the interacting boson–fermion model generalized by considering an np-boson and the single nucleon as a vector coupled in isospin to the bosons to form the model isospin invariant. The transitional interacting boson–fermion model Hamiltonians in IBFM-1 and IBFM-3 versions based on affine SU(1,[Formula: see text]1) Lie algebra are employed to describe the evolution from the spherical to deformed gamma unstable shapes along the chain of Cu isotopes. We have studied the energy spectra of [Formula: see text] isotopes and B(E2) transition probabilities of [Formula: see text] isotopes in the shape phase transition region between the spherical and gamma unstable deformed shapes. Good agreement was achieved between the calculated results using the models and measured data. The results obtained and the values of control parameters used in this calculation indicated that the odd-mass Cu isotopes located near the closed shell provided good examples of [Formula: see text](5) symmetry without any significant deformed gamma-unstable structure. Some comparisons are made with IBFM-1.

Structure of the low-lying positive and negative parity states in even–even 144−154Nd isotopes

2019 ◽  
Vol 28 (12) ◽  
pp. 1950107
Author(s):  
Hussein N. Qasim ◽  
Falih H. Al-Khudair
Keyword(s):  
Potential Energy Surfaces ◽  
Transition Probability ◽  
Model Space ◽  
Negative Parity ◽  
Energy Spectra ◽  
Interacting Boson Model ◽  
Nd Isotopes ◽  
Nd Isotope ◽  
Boson Model ◽  
Energy Surfaces

The low-lying positive and negative parity states of even–even [Formula: see text]Nd isotopes are studied using the interacting boson model (IBM). The negative parity states are involved within the IBM model by adding a single angular momentum ([Formula: see text]) boson with intrinsic negative parity [Formula: see text]-boson to [Formula: see text] and [Formula: see text]-bosons model space. For these nuclei, the potential energy surfaces [Formula: see text], transition probability [Formula: see text], [Formula: see text] and [Formula: see text] are calculated. Phase transition from the [Formula: see text] limit to the [Formula: see text] limit is observed in the chain and the critical point has been determined for [Formula: see text]Nd isotope. It is found that the calculated positive and negative parity energy spectra of Nd-isotopes agree well with the experimental data.

Description of the Ba–Dy(N = 92) nuclei in the interacting boson model

2017 ◽  
Vol 26 (04) ◽  
pp. 1750019 ◽  
Author(s):  
Huda H. Kassim
Keyword(s):  
Potential Energy Surfaces ◽  
Energy Levels ◽  
Interacting Boson Model ◽  
Contour Plot ◽  
Model Parameters ◽  
Transition Rates ◽  
Ground State Band ◽  
State Band ◽  
Boson Model ◽  
Energy Surfaces

Interacting Boson Model (IBM -1) has been used to study the energy levels and [Formula: see text] transition rates in Ba–Dy ([Formula: see text]) isotones. A simplified Hamiltonian is used which is written in the creation and annihilation form and for each nucleus, by fitting the selected experimental energy levels and [Formula: see text] transition rates with the calculated ones to get the best model parameters. Using the (IBM) Hamiltonian with an intrinsic state formalism, the potential energy surfaces (PES) for even–even Ba–Dy nuclei have been obtained and the contour plot of PES show that the shape phase transitions from spherical [Formula: see text] to deformed shape [Formula: see text] has been determined for the [Formula: see text], while [Formula: see text]Ce, [Formula: see text]Nd, [Formula: see text]Sm, [Formula: see text]Gd and [Formula: see text]Dy nuclei are deformed and have rotational-like characters. The behavior of energy and [Formula: see text] ratios in the ground state band are examined.

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