Proton and neutron exchange as a prelude to fusion at near-barrier energies

Authors :: Johnstone, J. E.
Singh, Varinderjit
Giri, R.
Hudan, S.
Vadas, J.
deSouza, R. T.
Ackermann, D.
Chbihi, A.
Hourdille, Q.
Abbott, A.
Balhoff, C.
Hannaman, A.
McIntosh, A. B.
Sorensen, M.
Tobin, Z.
Wakhle, A.
Yennello, S. J.
Famiano, M. A.
Brown, K. W.
Santamaria, C.
Lubian, J.
Soler, H. O.
Carlson, B. V.
Publication Year :: 2022
Abstract: Systematic examination of fusion for $^{39,41,45,47}$K + $^{28}$Si and $^{36,44}$Ar + $^{28}$Si provides insight into the impact of neutron and proton exchange on fusion for nuclei at and near the N=20 and N=28 shells. Comparison of the reduced excitation functions reveals a marked difference between the behavior of open-shell and closed-shell systems. While coupled channels calculations provide a good description for the closed-shell nuclei they significantly under-predict the fusion cross-section for open-shell nuclei. The observed trends are examined in the context of a potential energy surface, including shell effects, and multi-nucleon exchange with consideration of Pauli-blocking.<br />Comment: 7 pages, 4 figures