Shell Model Calculations for N=Z Nuclei in fpg Shell


AKKOYUN S., BAYRAM T.

Çukurova II. Uluslararası Multidisiplliner Çalışmalar Kongresi, Adana, Turkey, 26 - 28 April 2019, vol.1, pp.267-271

  • Publication Type: Conference Paper / Full Text
  • Volume: 1
  • City: Adana
  • Country: Turkey
  • Page Numbers: pp.267-271

Abstract

Nuclear excited state energies, nuclear spins and parities can be theoretically calculated successfully by nuclear shell model. This model is similar to the shell model of electrons in atoms. In this model, protons and neutrons fill the nuclear shells from lowest energy state to highers. In the model, there are magic numbers. These numbers are determined as 2, 8, 20, 28, 50, 82, 126. The nuclei having the magic numbers for proton or/and neutron are named as closed shell nuclei and these nuclei are used as inert core. Examples of these closed-shelled nuclei are given as He-4, O-16, Ca-40, Ni-56, Pb-208. It is assumed that the nucleons in the inert core do not move. Only valance nucleons out of the core are considered in the calculations. The self-conjugate (N=Z) moderate mass nuclei in fpg shell are one of the region for the investigation of several phenomena because of the maximum spatial overlap of neutrons and protons. The examples for these phenomena are isospin symmetry, shape coexistence, shape transition and
neutron-proton pairing interaction. In this study, the nuclear energy levels of N=Z nuclei in fpg shell have been calculated in the scope of the nuclear shell model by using KShell computer code. This code enables us to perform nuclear shell-model calculations with M-scheme representation. The code is easily used on a Linux PC with a many-core CPU and OpenMP library. It is also used on a state-of-the-art massive parallel computer with hybrid MPI+OpenMP parallel programming. It can compute energy levels, spin, isospin, magnetic and quadrupole moments, E2/M1 transition probabilities, and one-particle
spectroscopic factors. In the calculations, doubly magic 56 Ni were taken as core and f7/2 , p3/2 , f5/2 , p1/2 and g9/2 single particle orbits were used as valance shell. Different two-body interactions between nucleons were used. Excited state spin, parity and energy values have been obtained for the isotopes. The results have been compared with each other and the available experimental values in the literature.