Neutron dynamics in the fusion of neutron-rich O ions with ${}^{12}$C

The fusion excitation function for ${}^{21}$O + ${}^{12}$C was measured for the first time and compared to the fusion of less neutron-rich isotopes. The impact of valence neutrons in the d${}_{5\mathrm{/}2}$ shell on the fusion excitation function is examined. The experimental data manifest a clear dependence of the extracted barrier height, V${}_B$, and barrier position, R${}_B$ on neutron excess. To assess the role of dynamics the experimental data are compared with both density constrained frozen Hartree Fock (DCFHF) and density constrained time-dependent Hartree Fock (DCTDHF) theories.