One-neutron transfer in Ni-Ni interactions below the barrier

Using γ-ray photopeak intensities, excitation functions of one-neutron transfer to excited states in reaction products have been measured from about 20% and 15% below the fusion barrier to above barrier energies for ${}_{}{}^{58}{}_{}{}^{}$Ni${+\mathrm{}}^{64}$Ni and ${}_{}{}^{64}{}_{}{}^{}$Ni${+\mathrm{}}^{64}$Ni reactions, respectively. For ${}_{}{}^{58}{}_{}{}^{}$Ni${+\mathrm{}}^{64}$Ni, the one-neutron transfer cross section is greater than 1 mb at 20% below the barrier. The results are well described by distorted-wave Born approximation calculations using spectroscopic factors deduced from light-ion transfer measurements.