Investigating the γ decay of Ni 65 from particle- γ coincidence data

The γ decay of Ni65 has been studied from particle-γ coincidence data on the Ni64(d,pγ)Ni65 reaction. γ-ray spectra at excitation energies below Ex≈2MeV have been studied and compared with previous measurements. Coincidences corresponding to Ex≈4.4-6.1MeV have been used to constrain the shape of the nuclear level density and γ-strength function of Ni65 by means of the Oslo method. The experimental γ-strength function presents an enhancement at γ energies below Eγ≈3MeV. In addition, a resonance-like structure centered at Eγ≈4.6MeV is seen together with accumulated strength at Eγ≈2.6-3.6MeV. The obtained results contribute to the systematic study of γ decay in the Ni isotopes, which is of great interest for the understanding of both single-particle and collective nuclear structure phenomena.