Proton-neutron symplectic model description of $^{20}$Ne

2021 ◽  
Author(s):  
H. G. Ganev
Keyword(s):  
Transition Probabilities ◽  
Irreducible Representations ◽  
Model Description ◽  
Excitation Energies ◽  
Microscopic Description ◽  
Dynamical Group ◽  
Rotational Bands ◽  
Enveloping Algebra ◽  
Model Hamiltonian ◽  
Model Approach

Abstract A microscopic description of the low-lying positive-parity rotational bands in $^{20}$Ne is given within the framework of the symplectic-based proton-neutron shell-model approach provided by the proton-neutron symplectic model (PNSM). For this purpose a model Hamiltonian is used which includes an algebraic interaction, lying in the enveloping algebra of the $Sp(12,R)$ dynamical group of the PNSM, that introduces both horizontal and vertical mixings of different $SU(3)$ irreducible representations within the $Sp(12,R)$ irreducible collective space of $^{20}$Ne. A good overall description is obtained for the excitation energies of the ground and first two excited $\beta$ bands, as well as for the ground state intraband $B(E2)$ quadrupole collectivity and the known interband $B(E2)$ transition probabilities between the low-lying collective states without the use of an effective charge.

scholarly journals Shell model description of heavy nuclei and abnormal collective motions

2018 ◽  
Vol 178 ◽  
pp. 02015
Author(s):  
Chong Qi
Keyword(s):  
Shell Model ◽  
Degrees Of Freedom ◽  
Large Scale ◽  
Model Description ◽  
Heavy Nuclei ◽  
Collective Models ◽  
Collective Behaviors ◽  
Electromagnetic Transition ◽  
Nuclear Shell ◽  
Model Approach

In this contribution I present systematic calculations on the spectroscopy and electromagnetic transition properties of intermediate-mass and heavy nuclei around 100Sn and 208Pb. We employed the large-scale configuration interaction shell model approach with realistic interactions. Those nuclei are the longest isotopic chains that can be studied by the nuclear shell model. I will show that the yrast spectra of Te isotopes show a vibrational-like equally spaced pattern but the few known E2 transitions show rotational-like behaviour. These kinds of abnormal collective behaviors cannot be reproduced by standard collective models and provide excellent background to study the competition of single-particle and various collective degrees of freedom. Moreover, the calculated B(E2) values for neutron-deficient and heavier Te isotopes show contrasting different behaviours along the yrast line, which may be related to the enhanced neutron-proton correlation when approaching N=50. The deviations between theory and experiment concerning the energies and E2 transition properties of low-lying 0+ and 2+ excited states and isomeric states in those nuclei may provide a constraint on our understanding of nuclear deformation and intruder configuration in that region.

SHAPE EVOLUTION OF 96ZR AND 96MО WITH EXCITATION ENERGY INCREASE

2019 ◽  
pp. 37-41
Author(s):  
M.A. Mardyban ◽  
D.A. Sazonov ◽  
E.A. Kolganova ◽  
R.V. Jolos
Keyword(s):  
Potential Energy ◽  
Excitation Energy ◽  
Transition Probabilities ◽  
Collective Excitations ◽  
Nuclear Model ◽  
Shape Evolution ◽  
Energy Increase ◽  
Excitation Energies ◽  
Satisfactory Description

The observed properties of the low-lying collective excitations of 96Zr and 96Mo are investigated in the framework of the collective quadrupole nuclear model with the Bohr Hamiltonian, whose potential energy has two minima – spherical and deformed. Satisfactory description of the excitation energies and E2 transition probabilities is obtained. It is shown that in the case of 96Zr both minima are sufficiently deep. However, in the case of 96Mo a deformed minimum is only outlined.

X-Ray Fluorescence Cross-Section Measurements in the Energy Range 4-18 keV

1995 ◽  
Vol 39 ◽  
pp. 845-855
Author(s):  
Krassimir N. Stoev ◽  
Joseph F. Dlouhy
Keyword(s):  
Cross Sections ◽  
Transition Probabilities ◽  
Weighted Average ◽  
Physical Parameters ◽  
Emission Rates ◽  
Excitation Energies ◽  
X Ray ◽  
Fluorescence Cross Section ◽  
Theoretical Results

K, L and M shell x-ray fluorescence cross sections have been measured for elements 11 ≤, Z ≤, 92 at excitation energies corresponding to weighted average energies of K-lines of Ti-K (4.558 keV), Fe-K (6,480 keV), Ge-K (10.024 keV), Se-K (11.391 keV) and Mo-K (17.805 keV) . The measurements were performed with an energy-dispersive x-ray spectrometer in a vacuum chamber using thin ultra-pure targets. Rh x-ray tube and secondary targets were used for excitation of x-ray radiation. The measured x-ray fluorescence cross-sections have been compared to previously published experimental and theoretical results. Presented data can be used for determination of physical parameters such as photoionization cross-sections, fluorescence yields, x-ray emission rates, Coster-Kronig transition probabilities and jump ratios.

scholarly journals UNQUENCHED QUARK MODEL DESCRIPTION OF CHARMONIUM

2011 ◽  
Vol 02 ◽  
pp. 178-182 ◽  
Author(s):  
P. GONZÁLEZ
Keyword(s):  
Quark Model ◽  
Model Description ◽  
Good Precision ◽  
Static Potential ◽  
Model Approach

We show that the charmonium spectrum may be reproduced to a good precision by means of a semirelativistic quark model approach based on a universal static potential effectively incorporating effects from sea quark-antiquark pairs. Detailed predictions for upcoming data are derived.

scholarly journals TWO PERMANENTS IN THE UNIVERSAL ENVELOPING ALGEBRAS OF THE SYMPLECTIC LIE ALGEBRAS

2009 ◽  
Vol 20 (03) ◽  
pp. 339-368 ◽  
Author(s):  
MINORU ITOH
Keyword(s):  
Lie Algebra ◽  
Lie Algebras ◽  
Universal Enveloping Algebra ◽  
Irreducible Representations ◽  
General Linear ◽  
Universal Enveloping Algebras ◽  
Enveloping Algebras ◽  
Enveloping Algebra ◽  
Central Elements ◽  
Orthogonal Lie Algebra

This paper presents new generators for the center of the universal enveloping algebra of the symplectic Lie algebra. These generators are expressed in terms of the column-permanent and it is easy to calculate their eigenvalues on irreducible representations. We can regard these generators as the counterpart of central elements of the universal enveloping algebra of the orthogonal Lie algebra given in terms of the column-determinant by Wachi. The earliest prototype of all these central elements is the Capelli determinants in the universal enveloping algebra of the general linear Lie algebra.

MICROSCOPIC SELF-CONSISTENT AND COLLECTIVE MODEL DESCRIPTION OF LOW-ENERGY NUCLEAR STRUCTURE

1989 ◽  
Vol 04 (09) ◽  
pp. 2063-2146 ◽  
Author(s):  
K. HEYDE
Keyword(s):  
Nuclear Structure ◽  
Degrees Of Freedom ◽  
Collective Motion ◽  
Collective Model ◽  
Model Description ◽  
Mixed Symmetry ◽  
Self Consistent ◽  
Closed Shells ◽  
Model Approach

In the present review, an attempt is made to approach the different facets of the nucleus at low excitation energy from both a microscopic, self-consistent and a collective model approach. Some attention is given on how to relate the two “opposite” approaches to nuclear structure. In a final chapter, we discuss some newly appreciated modes in the nucleus that are specific to the proton and neutron degrees of freedom e.g. the study of intruder states near closed shells and the presence of proton-neutron mixed-symmetry collective motion.

Atomic structure and radiative properties of He-like Ni26+ ion in dense plasma

2021 ◽  
Author(s):  
Mayank Dimri ◽  
Dishu Dawra ◽  
A.K. Singh ◽  
Alok K.S. Jha ◽  
Rakesh Kumar Pandey ◽  
...  
Keyword(s):  
Quantum Number ◽  
Transition Probabilities ◽  
Principal Quantum Number ◽  
Model Potential ◽  
Oscillator Strengths ◽  
Radiative Properties ◽  
Configuration Interaction Method ◽  
Excitation Energies ◽  
Plasma Energy ◽  
Plasma Background

The influence of plasma screening on the excitation energies and transition properties of He-like Ni<sup>26+</sup> ion under strongly coupled plasma background has been analyzed. To perform the analysis, the multiconfiguration Dirac-Fock method has been adopted by incorporating the ion sphere model potential as a modified interaction potential between the electron and the nucleus. For comparison purposes, parallel calculations have been carried out using the modified relativistic configuration interaction method. It is found that the plasma energy shifts corresponding to principal quantum number conserving transitions (Δ n = 0) are blue shifted, whereas red shifted for the transitions where the principal quantum number is not conserved (Δn ≠ 0). The variation of transition probabilities and weighted oscillator strengths with free electron densities has also been studied. The present results should be advantageous in the modeling and diagnostics of astrophysical and laboratory plasmas.

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