scholarly journals Configuration Mixing for Po Isotopes within the Interacting Boson Model-2

2021 ◽  
Vol 66 (7) ◽  
pp. 582
Author(s):  
L.A. Najam ◽  
S.N. Abood ◽  
F.M.A. Al-Jomaily

We analyze a sequence of 194−204Po isotopes, using the Configuration Mixing (CM) Interacting Boson Model 2 (IBM-2). We set the parameters of Hamiltonian using a least-square fit for the known energy levels, electrical transition rates B(E2), and quadruple moments Q(2+1) for the first excited states. We have a good agreement with the experimental values for all the observables tested, and we infer that the feature of the shape coexistence is concealed in the isotopes of Po, just as in the isotopes of Os and Pt.

Author(s):  
Chengfu Mu ◽  
Dali Zhang

Abstract We have investigated the low-lying energy spectrum and electromagnetic transition strengths in even-even $^{76}$Se using the proton-neutron interacting boson model (IBM-2). The theoretical calculation for the energy levels and $E2$ and $M1$ transition strengths is in good agreement with the experimental data. Especially, the excitation energy and $E2$ transition of $0^+_2$ state, which is intimately associated with shape coexistence, can be well reproduced. The analysis on low-lying states and some key structure indicators indicates that there is a coexistence between spherical shape and $\gamma$-soft shape in $^{76}$Se.


2020 ◽  
Vol 928 (7) ◽  
pp. 072124
Author(s):  
Yasir Yahya Kassim ◽  
Mushtaq Abed Al-Jubbori ◽  
Imad Mamdouh Ahmed ◽  
Hewa Y. Abdullah ◽  
Fadhil I. Sharrad

Abstract The properties of 170 Er, 172Yb, 174Hf, and 176Wisotones have been studied and their energy states calculated. To identify the properties of each isotone, the values of the first excited states, E 2 1 + and the ratio of the second excited states to the first excited states, R 4 / 2 = E 4 1 + / E 2 1 + for all nuclei under consideration were adopted. To determine the properties of each nucleus, the relationship between the moment of inertia 2𝜗/ℏ 2 and the square of the angular frequency, ℏ 2 𝜔 2, the relationship between successive excited states to those preceding them r ( I + 2 ) I ) and the ΔI = 1 staggering between the GSB and the NPB states were studied for all states of 170Er, 172Yb, 174Hf, and 176W isotones. After identifying the properties of each isotone, the rotational limit in the interacting boson model IBM-1 and the IVBM model was used to calculate the energy states for each isotone and the results were compared with the experimental values. and good agreement was observed with some exception. The inaccuracy of some calculations in the IBM-1 results from the lying of some high states out the range of the rotational properties that were used.


2020 ◽  
pp. 149-152

The energy states for the J , b , ɤ bands and electromagnetic transitions B (E2) values for even – even molybdenum 90 – 94 Mo nuclei are calculated in the present work of "the interacting boson model (IBM-1)" . The parameters of the equation of IBM-1 Hamiltonian are determined which yield the best excellent suit the experimental energy states . The positive parity of energy states are obtained by using IBS1. for program for even 90 – 94 Mo isotopes with bosons number 5 , 4 and 5 respectively. The" reduced transition probability B(E2)" of these neuclei are calculated and compared with the experimental data . The ratio of the excitation energies of the 41+ to 21+ states ( R4/2) are also calculated . The calculated and experimental (R4/2) values showed that the 90 – 94 Mo nuclei have the vibrational dynamical symmetry U(5). Good agreement was found from comparison between the calculated energy states and electric quadruple probabilities B(E2) transition of the 90–94Mo isotopes with the experimental data .


Open Physics ◽  
2008 ◽  
Vol 6 (3) ◽  
Author(s):  
Mahmut Böyükata ◽  
İhsan Uluer

AbstractThe even-even Selenium isotopes in the A∼80 mass region and the general features of its structure have been investigated within the framework of the interacting boson model-2. The neutron proton version of the model has been applied to the Se (A=74 to 80) isotopes with emphasis on the description of the 01+, 21+, 02+, 22+ and 41+ states. The energy levels, B(E2)and B(M1)electromagnetic transition probabilities were calculated. The results of these calculations were compared with previous experimental results and were shown to be in good agreement.


2001 ◽  
Vol 79 (7) ◽  
pp. 999-1009 ◽  
Author(s):  
C Colón ◽  
A Alonso-Medina

Radiative transition probabilities for 190 lines arising from the ns 2S1/2, np 2P1/2,3/2, nd 2D3/2,5/2, nf 2F5/2,7/2, and 6p2 (4P1/2,3/2,5/2, 2D3/2,5/2, 2P1/2,3/2, and 2S1/2) levels of Pb(II) have been calculated. Lifetimes of the above mentioned levels have been determined from the present transition probabilities. These values were obtained in intermediate coupling (IC) and using ab initio relativistic Hartree-Fock calculations. For the IC calculations, we use the standard method of least-square fitting of experimental energy levels by means of computer codes from Cowan. The results of calculations for radiative transition probabilities and excited states lifetimes are presented and compared with the experimental results present in the literature and with other theoretical values. There is generally good agreement between our values and the experimental data available. Analysis of the interaction shows that the level 4P5/2 of the 6s6p2 configuration presents a large contribution to the 2D5/2 level of the 6s26d configuration. This result explains the good agreement between our result and the experimental values obtained to the observed as the 6s6p2 4P5/2 – 6s 25f2F7/2 dipole-forbidden transition. PACS Nos.: 32.70^*, 32.70Fw, 32.70Cs


Open Physics ◽  
2006 ◽  
Vol 4 (1) ◽  
pp. 124-154 ◽  
Author(s):  
Nurettin Türkan ◽  
Davut Olgun ◽  
Ýhsan Uluer

AbstractIn this study, we determined the most appropriate Hamiltonian that is needed for present calculations of nuclei in the A≅ 80 region by the view of interacting boson model (IBM-2). Using the best-fitted values of parameters in the Hamiltonian, we have calculated energy levels and B(E2) values for a number of transitions in some doubly even Se nuclei. The results were compared with the previous experimental and theoretical data and it is observed that they are in good agreement. The calculations have been extended to Se isotopes with A < 76 for which some B(E2) values are still not known.


Author(s):  
Omar Ahmed Muaffaq

In this study we calculated the energy levels of low lying structure for 104 – 108 Cd isotopes and the reduced transition B(E2) of even – even Cd nuclei for A=104,106, 108 by using" the interaction boson model IBM-1" and compared with experimental values .The ratio R(4/2) for the energy levels for 41 + and 21 + states were also calculated for those isotopes .The 104 – 108 Cd nuclei in " U(5) – O(6) transitional symmetry" were studied .The contour plots of the potential energy surfaces (P E S) was calculate for the isotopes above .


Author(s):  
Anwer A. Al-Sammarraie , Et. al.

Nuclear excited states with T > 0 in sd even-even N=Z  nuclei have been studied by using shell model. The calculations have employed the USDB Hamiltonian in order to predict the energy levels, the reduced electric quadrupole transition probabilities and reduced magnetic dipole transition probabilities. The study also include the average number of nucleons in each sd- active orbitals. The results compared with available experimental data.  The comparison showed a good agreement between theoretical and experimental energy sates for most of the states studied in this work. On the other hand there was a difference between theoretical and experimental values of transition probabilities, but it can be said that it remained within the acceptable range of the difference.


Sign in / Sign up

Export Citation Format

Share Document