Theory of synthesis of superheavy elements

The dynamical process of synthesizing superheavy elements is studied on the basis of the fluctuation-dissipation dynamics. A three-dimensional Langevin equation is used for the formation process of the superheavy compound nuclei in the spherical region. For the description of the surviving process, a one-dimensional Smoluchowski equation is adopted taking into account the temperature dependent shell correction energy and the competition between fission and neutron evaporations are described with the statistical model. Owing to the smaller hindrance for fusion, the fusion probability is larger for more asymmetric incident channels. On the other hand, such combinations lead the compound system to the relatively high excitation energy, comparing with when one uses the symmetric channel. In view of the Q-value of the reaction, the use of magic nuclei as target and projectile is preferable. The maximum residue cross section is obtained around the Bass barrier energy for the case of hot fusion reaction. The results show the importance of the use of neutron-rich beams and targets. (author)