Formation of hyperdeformed states by neutron emission from a dinuclear system
Abstract
The hyperdeformed nuclei treated as dinuclear or quasimolecular configurations are suggested to be directly produced in heavy-ion reactions at bombarding energies near the Coulomb barrier. The excited dinuclear system formed in the entrance channel of the heavy-ion collision can be cooled down by neutron emission to be transformed into the hyperdeformed nuclear system. This transition from the excited dinuclear system to a hyperdeformed configuration is described within the statistical approach. The reactions $^{48}\mathrm{Ca}+^{124,128,130,132,134}\mathrm{Sn}$, $^{48}\mathrm{Ca}+^{136,138}\mathrm{Xe}$, $^{48}\mathrm{Ca}+^{137,138,140}\mathrm{Ba}$, $^{40}\mathrm{Ca}+^{83,84}\mathrm{Kr}$, $^{48}\mathrm{Ca}+^{83,84,86}\mathrm{Kr}$, $^{40,48}\mathrm{Ca}+^{40,48}\mathrm{Ca}$, $^{58,60}\mathrm{Ni}+^{58,60}\mathrm{Ni}$, and $^{40}\mathrm{Ca}+^{58}\mathrm{Ni}$ are suggested for the population of hyperdeformed states. The production cross sections, quadrupole moments, and moments of inertia of hyperdeformed states formed in these reactions are calculated, and the optimal conditions for the experimental identification of such states are proposed.