Exotic neutron magicities of the proton magic Ni isotopes

The search for doubly magic isotopes of Ni began with ⁵⁸Ni, which exists naturally, as a stable isotope. And Ni is unique in having three doubly magic isotopes. ⁵⁶Ni and ⁷⁸Ni is actually one of the most neutron rich nuclei. ⁴⁸Ni is also reported as doubly magic; arised when the neutron and proton numbers are exchanged, ie., the mirror nucleus of ⁴⁸Ca and both are doubly magic. A sudden shortening of half-lives of Ni isotopes noticed beyond N=50 by Xu et al. in the measurement of β-decay half-lives of ^76,77Co, ^79,80Ni and ⁸¹Cu and the gross property of the half-life evolution suggests a doubly magic character of the neutron rich nucleus ⁷⁸Ni. In fact the experimental progress allows us to study more and more exotic systems towards the still unknown