7 research outputs found
Nucleon deformation in finite nuclei
The deformation of a nucleon embedded in various finite nuclei is considered
by taking into account the distortion of the chiral profile functions under the
action of an external field representing the nuclear density. The baryon charge
distribution of the nucleon inside light, medium-heavy and heavy nuclei is
discussed. The mass of the nucleon decreases as it is placed deeper inside the
nucleus and reaches its minimum at the center of the nucleus. We discuss the
quantization of non-spherical solitons and its consequences for the mass
splitting of the delta states. We show that bound nucleons acquire an intrinsic
quadrupole moment due to the deformation effects. These effects are maximal for
densities of nuclei about \rho(R)\sim 0.3...0.35 \rho(0). We also point out
that scale changes of the electromagnetic radii can not simply be described by
an overall swelling factor.Comment: 29 pp, REVTeX, 8 figures, more detailed discussion on quantization
and intrinsic quadrupole moments, references adde
Electromagnetic form factors of bound nucleons revisited
We investigate the possible modifications of the nucleons' electromagnetic
form factors in the framework of a modified Skyrme model allowing for
nucleon deformation and using realistic
nuclear mass distributions. We show that such effects are small in light nucle
Entrance channel effect on the formation of heavy and superheavy nuclei
We study the effect of the entrance channel and the shell structure of reacting massive nuclei on the fusion mechanism and the formation of evaporation residues of heavy and superheavy nuclei. In the framework of the combined dinuclear system concept and advanced statistical model, we analyze the 40Ar + 176Hf, 86Kr + 130Xe and 124Sn + 92Zr reactions leading to 216Th*; the 32S + 182W, 48Ti + 166Er, and 60Ni + 154Sm reactions leading to 214Th*; the 40Ar + 181Ta reaction leading to 221Pa *; the 48Ca + 248Cm reaction leading to the 296116 compound nucleus. In our calculations of the excitation functions for capture, fusion and evaporation residues we use the relevant variables such as mass-asymmetry of nuclei in the entrance channel, relative distance between nuclear centers, shell effect and shape of colliding nuclei and such characteristics of the reaction mechanism as potential energy surface, driving potential, the dependence of capture, fusion cross sections and survival probability of compound nucleus on the orbital angular momentum. As a result we obtain a beam energy range for the capture of the nuclei before the system fuses and the Γ/Γf ratio at each step along the de-excitation cascade of the compound nucleus. Calculations allow us to reach useful conclusions about the mechanism of the fusion-fission process, that is in competition with the quasifission process, and the production of the evaporation residues. © 2003 The Physical Society of Japan.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Formation of heavy and superheavy elements by reactions with massive nuclei
The effects of the entrance channel and shell structure on the experimental evaporation residues have been studied by analyzing the 32S + 182W, 48Ti + 166Er and 60Ni + 154Sm reactions leading to 214 Th*; the 40Ar + 181Ta reaction leading to 221Pa*; the 48Ca + 243Am, 248Cm, 249Cf reactions leading to the 29115, 296116 and 297118 superheavy compound nuclei, respectively. The fusion mechanism and the formation of evaporation residues of heavy and superheavy nuclei have been studied. In calculations of the excitation functions for capture, fusion and evaporation residues we used such characteristics as mass asymmetry of nuclei in the entrance channel, binding energies and shape of colliding nuclei, potential energy surface, driving potential, partial-fusion cross-sections and survival probability of the compound nucleus, Γn/Γf ratio at each step along the de-excitation cascade of the compound nucleus. The calculations have allowed us to make useful conclusions about the mechanism of the fusion-fission process, which is in competition with the quasifission process, and the production of the evaporation residues.SCOPUS: ar.jinfo:eu-repo/semantics/publishe