Transition strengths ↓
2
. u . w
2) M(E for gamma transition from first excited 21
+
states to the
ground states that produced by pure electric quadrupole emission in even –even isotopes of
56Ba and 62Sm have been studied through half- lives time for 21
+
excited states with the
intensities of γ0- transitions measurements and calculated as a function of neutron number
(N). The results thus obtained have shown that; the nuclides with magic neutron number such
as 56Ba
138
and 62Sm
144
have minimum value for ↓
2
. u . w
2) M(E .
Electric Quadrupole transitions are calculated for beryllium isotopes (9, 10, 12 and 14). Calculations with configuration mixing shell model usually under estimate the measured E2 transition strength. Although the consideration of a large basis no core shell model with 2ℏtruncations for 9,10,12 and14 where all major shells s, p, sd are used, fail to describe the measured reduced transition strength without normalizing the matrix elements with effective charges to compensate for the discarded space. Instead of using constant effective charges, excitations out of major shell space are taken into account through a microscopic theory which allows particle–hole excitations from the core and model space orbits to all higher orbits
... Show MoreThe reduced electric quadrupole transition strengths B(E2) from the first excited
2+ state to the ground 0+ state of some even-even Neon isotopes (18,20,22,24,26,28Ne)
have been calculated. All studied isotopes composed of 16O nucleus that is
considered as an inert core and the other valence particles considered to move over
the sd-shell model space within 1d5/2, 2s1/2 and 1d3/2 orbits.
The configuration mixing shell model with limiting number of orbitals in the
model space outside the inert core fail to reproduce the measured electric transition
strengths. Therefore, and for the purpose of enhancing the calculations, the
discarded space has been included through a microscopic theory which considers a
particle-
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 exp
... Show MoreQuadrupole transition rates and effective charges are calculated for even-even Si,
S and Ar isotopes based on sd and sdpf -shell model spaces. Shell model
calculations are performed with sd shell-model space for neutron number (N) ≤ 20
and sdpf shell-model space for N > 20. Excitation out of major shell space are taken
into account through a microscopic theory which allows particle-hole excitation
from the core and model space orbits to all higher orbits with 2 excitation.
Effective charges are obtained for each isotope. The results show a systematic
increase in the B(E2) values for N 20. Shell model calculation predicts the erosion
of the N=28 magicity in the neutron rich 42Si. No clear indications abo
In the present work, the magnetic dipole and electric quadrupole moments for some sodium isotopes have been calculated using the shell model, considering the effect of the two-body effective interactions and the single-particle potentials. These isotopes are; 21Na (3/2+), 23Na (3/2+), 25Na (5/2+), 26Na (3+), 27Na (5/2+), 28Na (1+) and, 29Na (3/2+). The one-body transition density matrix elements (OBDM) have been calculated using the (USDA, USDB, HBUMSD and W) two-body effective interactions carried out in the sd-shell model space. The sd shell model space consists of the active 2s1/2, 1d5/2,
... Show MoreThe interacting boson models, and were used to perform a complete study of even –even 160-168Yb isotopes .The low –lying positive parity states, dynamic symmetries, reduced electric quadrupole transition probability , quadruple momentum , and potential energy surface for 160-168Yb were investigated. Energy level sequences and energy ratios showed the gradual transition of the properties of these nuclei from the γ-unstable features to the rotational features . Adding the pairing parameter to Hamiltonian had a very slight effect on this feature, but it raised the β band, since it represents symmetry breaking such as in γ-unstable features . This applie
... Show MoreNuclear shell model is adopted to calculate the electric quadrupole moments for some Calcium isotopes 20Ca (N = 21, 23, 25, and 27) in the fp shell. The wave function is generated using a two body effective interaction fpd6 and fp space model. The one body density matrix elements (OBDM) are calculated for these isotopes using the NuShellX@MSU code. The effect of the core-polarizations was taken through the theory microscopic by taking the set of the effective charges. The results for the quadrupole moments by using Bohr-Mottelson (B-M) effective charges are the best. The behavior of the form factors of some Calcium isotopes was studied by using Bohr-Mottelson (B-M) effective charges.
The Nuclear structure of 110-116Cd isotopes was studied theoretically in the framework of the interacting boson model of IBM-l and IBM-2. The properties of the lowest mixed symmetry states such as the 1+, 2+ and 3+ levels produced by the IBM-2 model in the vibrational-limit U(5) of Cd - isotopes are studied in details. This analysis shows that the character of mixed symmetry of 2+ is shared between and states in 110-114Cd – isotopes, the large shar goes to s, while in isotope, the state is declared as a mixed symmetry state without sharing. This identification is confirmed by the percentage of F-spin contribution. The electromagnetic properties of E2 and Ml operators were investigated and the results were analyzed. Various
... Show MoreInteracting boson model version one has been used in the present
theoretical calculations. The energy levels & their transitions for dynamical symmetry 0(6), SU(3), U(5), ground-state band, Beta band, Gamma band, B(E2), Ot, B(Ml), ,u,gt and 6(£2/Ml)have been calculated to deduce the limit of Pt-198, Z=78. The present results confirmed the nuclear behavior of this isotope lay in the
transitional region 0(6), SU(3) U(5). The calculations of 021 + & 022+
showed that the shape of this isotope is oblate according to Q21+ and pr
... Show More