Assessing the impact of valence sd neutrons and protons on fusion

Experimental above-barrier fusion cross-sections for 17F + 12C are compared to the fusion excitation functions for 16,18O, 19F, and 20Ne ions on a carbon target. In comparing the different systems both the differing static size of the incident ions and changes in fusion barrier are accounted for by examining the reduced fusion cross-section. Remaining trends of the fusion cross-section above the barrier which reflect the sensitive interplay of the sd protons and neutrons are observed. The experimental data are also compared to both a widely-used analytical model of near-barrier fusion, as well as a time-dependent Hartree-Fock model. Both models fail to describe the trends observed.