Nurettin Türkan

IBM-2 calculations of some even-even selenium nuclei

In this study, we determined the most appropriate Hamiltonian that is needed for present calculations of nuclei in the A≅ 80 region by the view of interacting boson model (IBM-2). Using the best-fitted values of parameters in the Hamiltonian, we have calculated energy levels and B(E2) values for a number of transitions in some doubly even Se nuclei. The results were compared with the previous experimental and theoretical data and it is observed that they are in good agreement. The calculations have been extended to Se isotopes with A < 76 for which some B(E2) values are still not known.

IBM-2 calculations of some even–even neodymium nuclei

In this study, we determined the most appropriate Hamiltonian that is needed for present calculations of nuclei in the A130 region by the view of projection of IBM-2 parameters onto IBM-1. The interacting boson model has been widely used for describing the quadrupole collective states of the medium heavy nuclei and no distinction is made between proton and neutron variables when the first version of the model (IBM-1) is applied. So, triaxiality can be described explicitly, through the introduction of cubic terms in the boson operators. However, the microscopic foundations state certainly that it is very important to describe the proton and neutron variables explicitly. This is also a generalized definition of the second version of the IBA-model (IBM-2 model). Using the best-fitted values of parameters in the Hamiltonian of the IBM-2, we have calculated energy levels and B(E2) values for a number of transitions in 144,146,148,150,152,154Nd. The results were compared with the previous experimental and theoretical data and it is observed that they are in good agreement. Many B(E2) values that are still not known so far are stated and the set of parameters used in these calculations is the best approximation that has been carried out so far. It has turned out that the interacting boson approximation (IBA) is fairly reliable for the calculation of spectra in the entire set of 144,146,148,150,152,154Nd isotopes.

Quadrupole moments of some nuclei around the mass of A ∼ 80: 76,78,80,82,84Kr and neighboring Se isotopes

The quadrupole moments of 76,78,80,82,84,88Kr and 74,76,78,80,82Se isotopes are investigated in terms of the interacting boson model (IBM), and it was found that a good description of them can also be concluded in this model. Before the quadrupole moments were calculated, the positive-parity states and electromagnetic-transition rates (B(E2)) of even-mass Kr nuclei have also been obtained within the framework of IBM. It was seen that there is a good agreement between the presented results and the previous experimental data. The quadrupole moments of the neighboring Se isotopes were also obtained and it was seen that the results are satisfactorily agree well with the previous experimental data.

The Investigation of Multipolarity of the Electromagnetic Transitions in Some Even-Even Hf Isotopes

The aim of this work is to describe the results of calculation of multipole mixtures in some even-even Hf isotopes. Deformed nuclei have been studied for many years and an enormous quantity of detailed spectroscopy now exsts. But yet, our understanding of these nuclei remains suprisingly limited. The medium-to heavy-mass hafnium (Hf) isotopes are located in the rare-earth mass region where well-deformed nuclei can be populated to very high spin. The IBA model [1] has been applied to deformed nuclei [2], usually with considerable success [3, 4]. As a result of the phenomenological description of deformed nuclei in IBM, Hf isotopes has been occupied along the SU(3)-O(6) leg of the IBM triangle. In this work, we have carried out calculations for such isotopes and obtained reasonably good agreement with emprical systematics in the region. The aim of this work is to describe the results of calculation of multipole mixtures in 174,176,178,180Hf.