Speaker
Description
The knowledge of the
optimal collision energies at synthesis of the new superheavy elements and of the
contributions of products formed in different reaction channels to the mixed mass
distributions measured in the experiments are of the interest of experimenters. The
dinuclear system (DNS) model \cite{} developed in cooperation between
researchers of the Joint Institute for Nuclear Physics in Dubna (Russia) and
Institute of Nuclear Physics of Academy of Science of Uzbekistan allows us to
calculate the partial cross sections of reaction channels of heavy-ion collisions. It
was found that the partial fusion probability decreases by the increase of the DNS
angular momentum. The intrinsic fusion barrier $B^*_{\rm fus}$ of the potential
energy surface for the DNS configurations with the small mass asymmetry
increases by the angular momentum, since the moment of inertia of the DNS
decreases causing the increase of the centrifugal force. One of proves of this
phenomenon is the observation of the alpha-particle and corresponding conjugate
residue nucleus in the incomplete fusion. It is well known that the incomplete fusion
products are observed in collisions of the relatively light nuclei ($^{12}$C,
$^{16}$O, $^{22}$Ne, $^{28}$Si, ...) with the rare Earth elements [2]. The
theoretical results show that the competition between different reaction channels
depends on the charge asymmetry $Z_P/Z_T$, ratios $A_P/Z_P$ and $A_T/Z_T$
of the mass and proton numbers in the projectile and target nuclei, orientation
angles of their axial symmetry and initial orbital angular momentum [3]. The last
two physical quantities can not be controlled in the experiments, therefore, their
role in the complete fusion mechanism can be studied mainly on the base of
theoretical models. The hindrance to complete fusion is studied as the increase of
yields of the quasifission products in the heavy ion collisions. 1. A. K. Nasirov {\it et
al}., Nucl. Phys. A {\bf 759}, 342 (2005). 2. Abhishek Yadav {\it et al}., Phys. Rev. C
{\bf 107}, 044605 (2023). 3. A. K. Nasirov {\it et al}., Eur. Phys. J. A {\bf 55}, 29
