Role of the “window” component of the friction tensor in the formation of superheavy nuclei

Abstract

Formation of superheavy nuclei is greatly hindered by the inner barrier and strong dissipation on the way from the contact point of two colliding nuclei to the compound nucleus configuration. One of the dissipation mechanisms is related to the exchange of particles across the window between two nuclei in relative motion, which is the ``window'' term in the ``wall-plus-window'' formula. By means of the dynamic analysis for the symmetric systems $^{132}\mathrm{Xe}$ + $^{132}\mathrm{Xe}$ and $^{136}\mathrm{Xe}$ + $^{136}\mathrm{Xe}$, we have shown that the window component of friction tensor retards the elongation of the fusing composite nucleus, decreases the height of the inner barrier, and hence increases the fusion probability. Therefore, the friction associated with ``window'' term enhances the formation cross sections of superheavy nuclei. Besides, we have shown the mass difference (in units of the temperature) of the fission and neutron emission saddle points as a function of mass number of the hassium isotopes, which may provide a useful reference for synthesis and study of the nuclei adjacent to the doubly magic nucleus $^{270}\mathrm{Hs}$.