Superheavy element production, nucleus-nucleus potential and mu-catalysis

The semi-microscopic potential between heavy nuclei is evaluated for various colliding ions in the approach of frozen densities in the framework of the extended Thomas-Fermi approximation with hbar^2 correction terms in the kinetic energy density functional. The proton and neutron densities of each nucleus are obtained in the Hartree-Fock-BCS approximation with SkM* parameter set of the Skyrme force. A simple expression for the nuclear interaction potential between spherical nuclei is presented. It is shown that muon bound with light projectile induces the superheavy elements production in nucleus-nucleus collisions.Comment: 9 pages, 4 figures, RevTex, Tours 5 Symposium on Nuclear Physics, Tours, August 200

Nuclear reactions in hot stellar matter and nuclear surface deformation

Cross-sections for capture reactions of charged particles in hot stellar matter turn out be increased by the quadrupole surface oscillations, if the corresponding phonon energies are of the order of the star temperature. The increase is studied in a model that combines barrier distribution induced by surface oscillations and tunneling. The capture of charged particles by nuclei with well-deformed ground-state is enhanced in stellar matter. It is found that the influence of quadrupole surface deformation on the nuclear reactions in stars grows, when mass and proton numbers in colliding nuclei increase.Comment: 12 pages, 10 figure

Model for compound nucleus formation in various heavy-ion systems

The statistical model for the calculation of the compound nucleus formation cross section and the probability of compound nucleus formation in heavy-ion collisions is discussed in detail. The light, heavy, and super-heavy nucleus-nucleus systems are considered in this model in the framework of one approach. It is shown that the compound nucleus is formed in competition between passing through the compound-nucleus formation barrier and the quasi-elastic barrier. The compound-nucleus formation barrier is the barrier separating the system of contacting incident nuclei and the spherical or near-spherical ground state of the compound nucleus. The quasi-elastic barrier is the barrier between the contacting and well-separated deformed ions. It is shown that the compound nucleus formation cross-section is suppressed when the quasi-elastic barrier is lower than the compound nucleus formation barrier. The critical value of angular momentum, which limits the compound nucleus formation cross-section values for light and medium ion-ion systems at over-barrier collision energies, is discussed in the model. The suppression of the compound nucleus formation cross-section even at small partial waves for very heavy ion-ion systems is obtained in the model. The values of the capture and compound nucleus formation cross-sections calculated for various light, heavy, and super-heavy nucleus-nucleus systems as well as the probability of the compound nucleus formation for super-heavy nuclei are well agreed with the available experimental data.Comment: 17 pages, 6 figures, 2 table

Production of super-heavy nuclei in hot-fusion reactions

A model for hot-fusion reactions leading to the synthesis of super-heavy nuclei is discussed. The values of the hot-fusion cross-sections obtained in the model agree with the available experimental data. The hot-fusion cross-sections are found for two different models of the fission barrier heights of super-heavy nuclei. The calculations of the cross-sections for the various hot-fusion reactions leading to the 119 and 120 elements are presented. Simple expressions useful for qualitative analysis of the cross-section for forming super-heavy nuclei are obtained. It is shown that the super-heavy nuclei production cross section is proportional to the transmission coefficient of the capture barrier, realization probability of the $xn$-evaporation channel, and exponentially depends on the quasi-elastic barrier, fusion reaction Q-value, compound nucleus formation barrier, neutron separation energies, and fission barrier heights.Comment: 16 pages, 12 figures, 1 table. arXiv admin note: text overlap with arXiv:2309.1499