The Total β-Half-Lives for Some Nickel Isotopes

. The first-forbidden transitions can play an important role in decreasing the calculated half-lives specially in environments. We calculate the allowed Gamow-Teller transitions in pn-QRPA model for even-even neutron-rich isotopes of nickel. The first forbidden transitions for even-even neutron-rich isotopes of nickel are calculated assuming the nuclei to be spherical. The Woods-Saxon potential basis has been used in our calculations. The calculated half-lives have been compared with the schematic model calculations and corresponding experimental data. Keywords: pn-QRPA approximation, Gamow-Teller, First forbidden transitions