Examination of the different roles of neutron transfer in the sub-barrier fusion reactionsS32+Zr94,96and40Ca+Zr94,96

Abstract

The sub-barrier capture (fusion) reactions $^{32}\mathrm{S}+^{90,94,96}\mathrm{Zr}$, $^{36}\mathrm{S}+^{90,96}\mathrm{Zr}$, ${}^{40}\mathrm{Ca}+^{90,94,96}\mathrm{Zr}$, and ${}^{48}\mathrm{Ca}+^{90,96}\mathrm{Zr}$ with positive and negative $Q$ values for neutron transfer are studied with the quantum diffusion approach and the universal fusion function representation. For these systems, the $s$-wave capture probabilities are extracted from the experimental excitation functions and are also analyzed. Different effects of the positive ${Q}_{xn}$-value neutron transfer in the fusion enhancement are revealed in the relatively close reactions $^{32}\mathrm{S}+^{94,96}\mathrm{Zr}$ and ${}^{40}\mathrm{Ca}+^{94,96}\mathrm{Zr}$.