Systematics of fusion probability in “hot” fusion reactions

摘要

The fusion probability in “hot” fusion reactions leading to the synthesis of superheavy nuclei is investigatednsystematically. The quasifission barrier influences the formation of the superheavy nucleus around the “island ofnstability” in addition to the shell correction. Based on the quasifission barrier height obtained with the Skyrmenenergy-density functional, we propose an analytical expression for the description of the fusion probability, withnwhich the measured evaporation residual cross sections can be reproduced acceptably well. Simultaneously,nsome special fusion reactions for synthesizing new elements 119 and 120 are studied. The predicted evaporationnresidual cross sections for 50Ti+249Bk are ∼10–150 fb at energies around the entrance-channel Coulomb barrier.nFor the fusion reactions synthesizing element 120 with projectiles 54Cr and 58Fe, the cross sections fall to a fewnfemtobarns, which seems beyond the limit of the available facilities.