Role of various nuclear densities and higher-order deformations on the dynamics of 16O+154Sm fusion reaction

Abstract

Understanding the role of nuclear structure in heavy-ion fusion reactions is crucial, especially in the low-energy regime where nuclear shape and density profiles significantly influence the reaction dynamics. In this work, we investigate the ${}^{16}O{+}^{154}\text{Sm}$ fusion reaction as an illustrative case by employing three different nuclear density descriptions, namely the relativistic mean-field (RMF) formalism, the Skyrme-Hartree-Fock (SHF) approach, and the two-parameter Fermi (2pF) formula. These densities are folded with relativistic R3Y and non-relativistic M3Y effective nucleon-nucleon (NN) interactions to obtain six different nuclear potentials. Furthermore, the role of quadrupole β₂ and higher-order hexadecapole β₄ deformations of the target nucleus is included in the calculations of nuclear densities, fusion barrier characteristics, and cross-sections. By comparing barrier heights at different orientations, it is observed that the M3Y interaction provides higher barriers than the R3Y interaction. Among the densities, the 2pF yields the highest fusion barrier, while the SHF yields the lowest. The inclusion of β₂ and β₄ deformations results in strong orientation dependence, modifying the fusion barrier, especially at ${\theta }_2=0^{\circ }$. Further, the inclusion of β₄ deformation of the ¹⁵⁴Sm results in a lowering of the fusion barrier height compared to only β₂ deformation, except for target orientation angles 36^∘ < θ₂ < 72^∘. The highest cross-sections are obtained with SHF densities, followed by RMF densities, whereas the 2pF densities underestimate the experimental data. A better match with the experimental cross-section is achieved when structural effects, such as β₂ and β₄ deformations, are included in the SHF and RMF densities, along with the R3Y NN interaction. These findings underline the importance of incorporating detailed nuclear structure effects for a reliable description of heavy-ion fusion dynamics.