Search

Nuclear structure (energy levels, elastic and inelastic electron-nucleus scattering, and transition probability) of $^{23}\mathrm{Na}$, $^{25}\mathrm{Mg}$, $^{27}\mathrm{Al}$, and $^{41}\mathrm{Ca}$ nuclei have been studied using shell-model calculations. A set of two-body interactions are used in this paper. The universal $sd$ of the Wildenthal interaction in the proton-neutron formalism, universal $sd$-shell interaction A, universal $sd$-shell interaction B, and GXFP1 interaction for the $fp$ shell is used with the nucleon-nucleon realistic interaction Michigan three-range Yakawa as a two-body interaction for core-polarization calculations. Two shell-model codes, cpm3y and nushell for Windows, have been used to calculate the results. The wave functions of radial single-particle matrix elements have been calculated with harmonic-oscillator and Woods-Saxon potentials. The level schemes are compared with the experimental data up to 5.776, 5.251, and 4.51 MeV for $^{23}\mathrm{Na}$, $^{25}\mathrm{Mg}$, and $^{27}\mathrm{Mg}$, respectively. Very good agreements are obtained for all nuclei in this study. Results from electron scattering form-factor calculations have shown that the core-polarization effects are essential to obtain a reasonable description of the data with no adjustable parameters.

In this work, the energy levels electromagnetic transition B(E2) and B(M1), branching ratios, mixing ratios and electric quadrupole moment of even-even 120-126Xe isotopes have been investigated using Interacting Boson Model (IBM-1). The results were compared with some previous experimental and theoretical values, it was seen that the obtained theoretical results are in agreement with the experimental data.

A description of the even–even Pt isotopes for A = 190 to 196 in the framework of the Interacting Boson Model (IBM-1) is carried out. Energy levels, B(E2) and B(M1) values, branching ratios, E2/M1 mixing ratios and QJ values of the above nuclei have been calculated. The energy levels, B(E2) values and the electric quadrupole moment QJ results are reasonably consistent with the experimental data. The magnetic dipole is compared with the available experimental data. Furthermore, the calculated results are better than previous studies.

Inelastic electron scattering form factors for 29 Si nucleus with total angular momentum and positive parity (Jπ) and excited energy (3/2+, 1.273 MeV; 5/2+, 2.028 MeV; 3/2+, 2.425 MeV and 7/2+, 4.079 MeV) have been calculated using higher energy configurations outside the sd-shell. The calculations of inelastic form factors up to the first- and second-order with and without core-polarization (CP) effects were compared with the available experimental data. The calculations of inelastic electron scattering form factors up to the first-order with CP effects are in agreement with the experimental data, excepted for states 3/2+(1.273 MeV) and 5/2+(2.028 MeV) and without this effect are failed for all states. Furthermore, the calculations of inelastic electron scattering form factors up to the second-order with CP effects are in agreement with the experimental data for 3/2+(1.273 MeV) and 5/2+(2.028 MeV).

The inelastic longitudinal form factors F(q) ’s, an expression for the transition charge density were studied where the deformation in nuclear collective modes besides the shell model transition density are taken into consideration. In this work, the core polarization transition density was evaluated by adopting the shape of Tassie model together with the form of the ground state two-body charge density distributions and the effect of two body short range correlation function. It was noticed that the core polarization effects, which represent the collective modes are essential in obtaining a good agreement between the calculated inelastic longitudinal F(q) ’s and those of the experimental data for 4He, 12C, 16O, 28Si, 32S and 40Ca nuclei. J.Natn.Sci.Foundation Sri Lanka 2013 41 (3): 209-217 DOI: http://dx.doi.org/10.4038/jnsfsr.v41i3.6053

The energy levels, transition energy, B(E2) values, intrinsic quadrupole moment Q0 and potential energy surface for even-even 184W and 184Os nuclei were calculated using IBM-1. The predicted energy levels, transition energy, B(E2) values and intrinsic quadrupole moment Q0 results are reasonably consistent with the experimental data. A contour plot of the potential energy surfaces shows that two interesting nuclei are deformed and have rotational characters.