Abstract.We have performed shell model calculations by means of Oxbash nuclear structure code using recent experimental single particle (spes) and single hole (shes) energies with valence space models above the 100 sn and 132 sn doubly magic cores. The two-body matrix elements (tbme) of original CD-Bonn realistic interaction are introduced after have been modified taking into account the three-body forces. We have focused our study on spectroscopic properties evaluation of 130 Sb, 132 Te and 134 I nuclei, in particular their energy spectra, transition probabilities and moments have been determined. The getting spectra are in reasonable agreement with the experimental data.

The interactions between the core which is anymore inert and the valence nucleons play a very important role in the interpretation of nuclear properties far from stability. The work done in this study is based on the calculations of energy spectra and electromagnetic properties for even-even isotones with N=52, in the 78 Ni region. Based on the interaction jj45apn with the space model jj45pn, we have realized some modifications considering the monopole interaction and a new interaction called jj45am is introduced. The calculations are performed in the framework of the nuclear shell model using the NuShellX@MSU code.The shell evolution, studied by estimating the effective single-particle energies (SPEs) in this region, show an important influence on the nuclear structure properties. The obtained results using the new interaction jj45am are in agreement with the experimental data, and better than those given by the original one jj45apn.

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Study of nuclear monopole interaction effects around closed shell cores provides important information on the shell evolution and the effective single-particle energies. In the aim of studying and understanding the role of these effects, and in order to resolve spectroscopic problems originated from the ignored three-body interactions, shell-model calculations have been realized for interpreting and developing the two-body matrix elements of N-N interaction. In this context, and in order to reproduce the nuclear spectra of odd-odd N = 81 isotones, we have performed some calculations using recent experimental single particle and single hole energies, by means of the Oxbash nuclear structure code. The two-body matrix elements (TBMEs) of the used effective interaction were deduced from the sn100pn realistic interaction for 100 Sn mass region, and the single particle or single hole energies were taken from 132 Sn mass region. The getting results for the one particle-one hole nucleus are in agreement with the experimental data. However, the new interaction cannot reproduce the experimental spectra of three particles-one hole and five particles-one hole isotones.

The spectra of nuclides involving few valence particles or holes far from β − stability are important tools to develop our knowledge about nuclear forces and N-N interaction. In order to understand the monopole interaction effect on the properties of nuclear structure of these nuclei, we have performed shell model calculations using recent experimental single particle energies, by means of Oxbash nuclear structure code. The two-body matrix elements of the effective interaction were deduced from those of kh5082 original interaction, taking into account the nuclear monopole effect in 132 Sn mass region. The obtained spectroscopic properties for 134 Te nucleus are in good agreement with the experiment.

Most of the elements heavier than Fe in the universe were produced by the so-called r-process. Its mechanism is based on a rapid neutron capture by the nuclei, so that the neutron capture rates are much faster than those of β -decay. When r-process reaches nuclei with magic neutron numbers, the neutron separation or binding energies increase and the process slows down, it has to wait for several β decays to produce heavier nuclei. These magic nuclei are the waiting points. Information about r-process are steel missing and it requires knowledge of the nuclear structure of the neutron rich nuclei. However, the nuclear properties of these nuclei are not sufficiently well understood due to the experimental difficulties in their production. The A=130 isobars with N=82 present one of the most interesting waiting points, because of their positions far from β stability and near the doubly magic 132Sn core, for which theoretical and experimental studies give important information about beta decay half-lives. In this context, we focus on the study of even-even 130 Cd waiting point nuclear properties. We have performed some spectroscopic calculations for energetic spectrum, β -decay half-life evolution in terms of temperature, using recent experimental data, by means of Oxbash nuclear structure code. The getting spectrum is in a reasonably agreement with the available experimental data. However, the calculated β-decay half-life for the studied waiting point is short in comparison with the experimental one.

Nuclear systems near nucleon drip lines have great importance in studying nucleon-nucleon force properties. However, such unstable systems have few experimental data. Due to technical development in recent years, new experimental data assembly provides huge information to analyze possible observation of new phenomena. In the aim of exploring proton-rich nuclei near closed shells, we have studied the even-even Z = N nuclei in 28 < Z < 50 , 50 < N < 82 mass region. This study is based on the investigation of the core polarization and the monopole effect originated from the interactions between the magic core and the valence nucleons. In this context, this work includes the calculation of the energy spectra of Zr, Mo, Ru, Pd and Cd nuclei. These calculations were performed in the framework of the nuclear shell model using NuShellX@MSU code. Using recent single-particle energies, the three-body effect consideration introduces some modifications on the effective interaction. By means of the modified interaction, some nuclear properties of the studied nuclei have been evaluated. The results show a reasonable agreement with the available experimental data. The monopole effect is an important component of nucleon-nucleon interaction, in which its consideration gives a reasonably agreement with available data.

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