arXiv subjects

Bakhodir Kayumov

Publications and source records attributed to Bakhodir Kayumov.

4 recordsLinked to original sources

arXiv2026

Coulomb and nuclear polarization of the nucleon density in the dinuclear configuration of the $^{40}$Ca + $^{208}$Pb system

The change of the nucleon density distribution of a heavy nucleus caused by the presence of a second nucleus at a fixed centre-to-centre distance is studied in the framework of the deformed Woods--Saxon mean field. The single-particle problem of one nucleus has been solved by diagonalization in a cylindrical harmonic oscillator basis with the external field of the partner nucleus included in the Hamiltonian before diagonalization. The external field consists of the Coulomb potential of the partner charge distribution and of the nuclear part obtained by double folding of the Migdal density-dependent effective nucleon-nucleon interaction, in the same form as it is used in the dinuclear system approach. The induced density change $δρ(\boldsymbol r;R)$ and the corresponding changes of the quadrupole moment, of the mean-square radius and of the interaction energy have been calculated for the $^{40}$Ca + $^{208}$Pb system at separations $R = 15.5$--$20$ fm. The results are compared with the first-order (linear-response) treatment of the same external field. The polarization of both partners is found to be dominated by the repulsive Coulomb tidal field, which produces an oblate deformation of the density, while the attractive nuclear field acts in the opposite sense and partially cancels the Coulomb contribution at the smallest separations. The polarization energy is found to be a dipole quantity, the induced quadrupole deformation contributing only a few percent of it. The limits of validity of the one-centre description are established quantitatively.

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arXiv2025

Investigation of the formation of superheavy elements with atomic numbers 116 and 120 through $^{50}$Ti-induced reaction

The synthesis of superheavy elements provides crucial insights into the stability and structure of nuclei at the limits of the periodic table. This study investigates the $^{50}$Ti$+^{244}$Pu and $^{50}$Ti$+^{251}$Cf reactions as pathways to form superheavy elements (SHEs) 116 (Livermorium) and 120, respectively. Using the dinuclear system model, key parameters such as fusion probability and fusion cross section were calculated. These findings were used to examine neutron emission and survival probability through a statistical approach. The reaction $^{50}$Ti$+^{244}$Pu is explored as a continuation of experimental efforts to extend the known isotopic range of element 116, while the $^{50}$Ti$+^{251}$Cf reaction represents a frontier for the synthesis of element 120. The role of shell effects, excitation energy, and angular momentum on the production and stability of these nuclei is discussed. The results provide theoretical predictions to guide future experimental efforts aimed at advancing our understanding of the island of stability and the limits of nuclear existence.

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arXiv2024

Optimal colliding energy for the synthesis of superheavy element $Z$=119

The evaporation residue (ER) cross section of 3n and 4n channels related to the synthesis of superheavy element (SHE) with the charge number $Z=119$ in the $^{51}$V+$^{248}$Cm reaction has been calculated by the dinuclear system (DNS) model as a sum of the partial cross sections of the corresponding channels. The angular momentum distribution of the compound nucleus is estimated by the dynamical trajectory calculations of the capture probability which is considered as the DNS formation probability. The fusion probability decreases by the increase of the DNS angular momentum due to its influence on the intrinsic fusion barrier $B_{\rm fus}^*$. The range $α_2=60^{\circ} ÷70^{\circ}$ of the orientation angle of the axial symmetry axis of the deformed target nucleus $^{248}$Cm is favorable for the formation of the compound nucleus. The fusion probability decreases at around $α_2=90^{\circ}$ since the number of the partial waves contributing to the capture decreases. Therefore, it is important to calculate the capture cross section dynamically. The 4n channel cross section of the SHE synthesis is larger than the 3n channel cross section maximum value of the ER cross section is 12.3 fb at $E_{\rm c.m.}$=232 MeV.

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arXiv2015

Peculiarities of quasifission reactions in heavy ion collisions

The probability of the formation and decay of a dinuclear system is investigated for a wide range of relative orbital angular momentum values. The mass and angular distributions of the quasifission fragments are studied to understand the reaction mechanisms of the heavy ion collision of $^{78}$Kr(10$A$ MeV) + $^{40}$Ca within dinuclear system model. The quasifission products are found to contribute to the mass-symmetric region of the mass distribution in collisions with a large orbital angular momentum. The analysis of mass and angular distributions of quasifission fragments shows the possibility of the $180^\circ$ rotation of the system so that projectile-like products can be observed in the forward hemisphere with large cross sections, which can explain the phenomenon observed recently in the ISODEC experiment.

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