NBCS approach to the effective boson number in the interacting boson model

1984 ◽  
Vol 39 (6) ◽  
pp. 89-95 ◽  
Author(s):  
G. Maino ◽  
A. Ventura
Keyword(s):  
Interacting Boson Model ◽  
Boson Number ◽  
Boson Model

scholarly journals Line of approximate SU(3) symmetry inside the symmetry triangle of the Interacting Boson Model

2020 ◽  
Vol 19 ◽  
pp. 16
Author(s):  
D. Bonatsos ◽  
S. Karampagia ◽  
R. F. Casten
Keyword(s):  
Phase Transition ◽  
Critical Line ◽  
Interacting Boson Model ◽  
Rigid Rotator ◽  
Symmetry Line ◽  
First Order ◽  
Boson Number ◽  
Boson Model ◽  
Shape Phase Transition ◽  
First Time

The U(5), SU(3), and O(6) symmetries of the Interacting Boson Model (IBM) have been traditionally placed at the vertices of the symmetry triangle, while an O(5) symmetry is known to hold along the U(5)–O(6) side of the triangle. We construct [1] for the first time a symmetry line in the interior of the triangle, along which the SU(3) symmetry is preserved. This is achieved by using the contraction of the SU(3) algebra to the algebra of the rigid rotator in the large boson number limit of the IBM. The line extends from the SU(3) vertex to near the critical line of the first order shape/phase transition separating the spherical and prolate deformed phases. It lies within the Alhassid–Whelan arc of regularity, the unique valley of regularity connecting the SU(3) and U(5) vertices amidst chaotic regions, thus providing an explanation for its existence.

scholarly journals Approximate symmetries in the Interacting Boson Model

2019 ◽  
Vol 18 ◽  
pp. 37
Author(s):  
D. Bonatsos
Keyword(s):  
Nuclear Structure ◽  
Dynamical Symmetry ◽  
Interacting Boson Model ◽  
Approximate Symmetries ◽  
Dynamical Symmetries ◽  
Boson Number ◽  
Boson Model

Dynamical symmetries have played a central role for many years in the study of nuclear structure. Recently, the concepts of Partial Dynamical Symmetry (PDS) and Quasi-Dynamical Symmetry (QDS) have been introduced. We shall discuss examples of PDS and QDS appearing in the large boson number limit of the Interacting Boson Mod

scholarly journals What can we learn from the Interacting Boson Model in the limit of large boson numbers?

2020 ◽  
Vol 16 ◽  
pp. 1
Author(s):  
D. Bonatsos ◽  
E. A. McCutchan ◽  
R. F. Casten
Keyword(s):  
Ordinal Number ◽  
Interacting Boson Model ◽  
Valence Nucleon ◽  
First Order ◽  
Effective Order ◽  
Boson Number ◽  
Boson Model ◽  
Special Solutions ◽  
Shape Phase Transition ◽  
Boson Approximation

Over the years, studies of collective properties of medium and heavy mass nuclei in the framework of the Interacting Boson Approximation (IBA) model have focused on finite boson numbers, corresponding to valence nucleon pairs in specific nuclei. Attention to large boson numbers has been motivated by the study of shape/phase transitions from one limiting symmetry of IBA to another, which become sharper in the large boson number limit, revealing in parallel regularities previously unnoticed, although they survive to a large extent for finite boson numbers as well. Several of these regularities will be discussed. It will be shown that in all of the three limiting symmetries of the IBA [U(5), SU(3), and O(6)], energies of 0+ states grow linearly with their ordinal number. Furthermore, it will be proved that the narrow transition region separating the symmetry triangle of the IBA into a spherical and a deformed region is described quite well by the degeneracies E(0^+_2 ) = E(6^+_1 ), E(0^+_3 ) = E(10^+_1 ), E(0^+_4 ) = E(14^+_1 ), the energy ratio E(6^+_1 )/E(0^+_2 ) turning out to be a simple, empirical, easy-to-measure effective order parameter, distinguishing between first- and second-order transitions. The energies of 0+ states near the point of the first order shape/phase transition between U(5) and SU(3) will be shown to grow as n(n+3), where n is their ordinal number, in agreement with the rule dictated by the relevant critical point symmetries studied in the framework of special solutions of the Bohr Hamiltonian. The underlying dynamical and quasi-dynamical symmetries are also discussed.

Energy Levels and Electromagnetic Transition of 90-94mo Nuclei Using Ibm-1

2020 ◽  
pp. 149-152
Keyword(s):  
Experimental Data ◽  
Transition Probability ◽  
Energy Levels ◽  
Dynamical Symmetry ◽  
Interacting Boson Model ◽  
Excitation Energies ◽  
Electromagnetic Transition ◽  
Boson Model ◽  
Energy States ◽  
Good Agreement

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 .

scholarly journals Role of Single-Particle Energies in Microscopic Interacting Boson Model Double Beta Decay Calculations

Universe ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 66
Author(s):  
Jenni Kotila
Keyword(s):  
Beta Decay ◽  
Single Particle ◽  
Field Potential ◽  
Double Beta Decay ◽  
Interacting Boson Model ◽  
Model Calculations ◽  
Single Particle Level ◽  
Particle Level ◽  
Boson Model

Single-particle level energies form a significant input in nuclear physics calculations where single-particle degrees of freedom are taken into account, including microscopic interacting boson model investigations. The single-particle energies may be treated as input parameters that are fitted to reach an optimal fit to the data. Alternatively, they can be calculated using a mean field potential, or they can be extracted from available experimental data, as is done in the current study. The role of single-particle level energies in the microscopic interacting boson model calculations is discussed with special emphasis on recent double beta decay calculations.

scholarly journals Octupole correlations in light actinides from the interacting boson model based on the Gogny energy density functional

2020 ◽  
Vol 102 (6) ◽  
Author(s):  
K. Nomura ◽  
R. Rodríguez-Guzmán ◽  
Y. M. Humadi ◽  
L. M. Robledo ◽  
J. E. García-Ramos
Keyword(s):  
Energy Density ◽  
Density Functional ◽  
Interacting Boson Model ◽  
Energy Density Functional ◽  
Model Based ◽  
Boson Model
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