In search of beyond mean-field signatures in heavy-ion fusion reactions

Examination of high-resolution, experimental fusion excitation functions for ${}^{16,17,18}$O + ${}^{12}$C reveals a remarkable irregular behavior that is rooted in the structure of both the colliding nuclei and the quasi-molecular composite system. The impact of the $\mathrm{\ell }$-dependent fusion barriers is assessed using a time-dependent Hartree-Fock model. Barrier penetrabilities, taken directly from a density-constrained calculation, provide a significantly improved description of the experimental data as compared to the standard Hill-Wheeler approach. The remaining deviations between the parameter-free theoretical mean-field predictions and experimental fusion cross sections are exposed and discussed.