Shape isomerism in Ni isotopes within RHB formalism

A systematic study of shapes in Ni (Z=28) isotopes (N=26-52) has been made in the Relativistic-Hartree-Bogoliubov (RHB) formalism using density-dependent zero and finite range NN interaction. The constraint calculations for both axial and triaxial symmetry has been done to obtain the potential energy surface (PES). γ-soft nature is found in almost all Ni isotopes. The shape of ⁵⁶Ni, ⁶⁸Ni and ⁷⁸Ni is most significant because of the presence of the magic neutron numbers. Shape isomerism in case of ^56,64,66,68Ni isotopes has been predicted. The trends of charge radii and neutron and proton radii are found to be consistent with the shape evolution along with the neutron numbers. The results obtained are in agreement with experiment and with other theoretical studies. (author)