Fission Barriers of Compound Superheavy Nuclei

The dependence of fission barriers on the excitation energy of the compound nucleus impacts the survival probability of superheavy nuclei synthesized in heavy-ion fusion reactions. In this work [1,2], we investigate the isentropic fission barriers by means of the self-consistent nuclear density functional theory. The relationship between isothermal and isentropic descriptions is demonstrated. Calculations have been carried out for $^{264}$Fm, $^{272}$Ds, $^{278}$Cp, $^{292}$114, and $^{312}$124. For nuclei around $^{278}$Cp produced in ``cold fusion" reactions, we predict a more rapid decrease of fission barriers with excitation energy as compared to the nuclei around $^{292}$114 synthesized in ``hot fusion'' experiments. This is explained in terms of the difference between the ground-state and saddle-point temperatures. \\[4pt] [1] J.C. Pei, W. Nazarewicz, J.A. Sheikh and A.K. Kerman, Phys. Rev. Lett. {\bf 102}, 192501 (2009).\\[0pt] [2] J.A. Sheikh, W. Nazarewicz, and J.C. Pei, Phys. Rev. C {\bf 80}, 011302(R) (2009).