Microscopic study on fusion reactions $^{40,48}\mathrm{Ca}+{}^{78}\mathrm{Ni}$ and the effect of tensor force

TL;DR

This study uses microscopic methods to analyze fusion reactions between calcium isotopes and nickel, revealing how tensor forces influence fusion barriers and cross sections, especially highlighting differences between $^{40}$Ca and $^{48}$Ca systems.

Contribution

It provides a detailed microscopic analysis of fusion reactions involving calcium isotopes and nickel, emphasizing the role of tensor forces on internuclear potentials and fusion cross sections.

Findings

Tensor force significantly affects internuclear potentials.

Sub-barrier fusion cross sections are enhanced for $^{40}$Ca+$^{78}$Ni.

Tensor force suppresses sub-barrier fusion in both systems.

Abstract

We provide a microscopic description of the fusion reactions between $^{40,48}$Ca and $^{78}$Ni. The internuclear potentials are obtained using the density-constrained (DC) time-dependent Hartree-Fock (TDHF) approach and fusion cross sections are calculated via the incoming wave boundary condition method. By performing DC-TDHF calculations at several selected incident energies, the internuclear potentials for both systems are obtained and the energy-dependence of fusion barrier are revealed. The influence of tensor force on internuclear potentials of $^{48}\mathrm{Ca}+{}^{78}\mathrm{Ni}$ is more obvious than those of $^{40}\mathrm{Ca}+{}^{78}\mathrm{Ni}$. By comparing the calculated fusion cross sections between $^{40}\mathrm{Ca}+{}^{78}\mathrm{Ni}$ and $^{48}\mathrm{Ca}+{}^{78}\mathrm{Ni}$, an interesting enhancement of sub-barrier fusion cross sections for the former system is found, which can be explained by the narrow width of internuclear potential for $^{40}\mathrm{Ca}+{}^{78}\mathrm{Ni}$ while the barrier heights and positions are very close to each other. The tensor force suppresses the sub-barrier fusion cross sections of both two systems.