Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4.0 International license. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

Export citation

Export citation

Choose format for download:

Download Citation
  • Open Access

Coulomb and nuclear polarization of the nucleon density in the dinuclear configuration of the Ca40+Pb208 system

Bakhodir Kayumov*

  • *Contact author: b.kayumov@newuu.uz

Phys. Rev. C 114, 044624 – Published 28 October, 2026

DOI: https://doi.org/10.1103/d6vs-ppv1

Abstract

The change of the nucleon density distribution of a heavy nucleus caused by the presence of a second nucleus at a fixed center-to-center 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 used in the dinuclear system approach. The induced density change δρ(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 Ca40+Pb208 system at separations R=15.5–20 fm. The results are compared with the first-order (linear-response) treatment of the same external field. Because the mean field is anchored at the origin, the multipole moments are shown to require a translationally invariant definition: a displaced but undeformed distribution acquires a quadrupole moment second order in the displacement, and in this problem that kinematic term is comparable with the induced moment itself. Once it is removed, the intrinsic quadrupole response of Pb208 agrees with the first-order one to better than half a percent, and remains so over the full range of the switching parameter for the Coulomb field at R=20 fm, while that of Ca40 retains a genuine higher-order contribution of 12% to 16%. The polarization of both partners is 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. At the larger separations the induced octupole deformation is close to 40% of the quadrupole one for Pb208 and to 50% for Ca40, and it is the more sensitive indicator of the breakdown of the one-center picture. The polarization energy is a dipole quantity, the induced quadrupole deformation contributing only a few percent of it; it is verified by coupling-constant integration and is quoted under several correction prescriptions for the spurious translational component and for the absence of the residual interaction. The sensitivity to the geometry of the folding densities and the limits of validity of the one-center description are established quantitatively.

View figure in article

Physics Subject Headings (PhySH)

Article Text

References (32)

  1. S. Hofmann and G. Münzenberg, The discovery of the heaviest elements, Rev. Mod. Phys. 72, 733 (2000).
  2. S. A. Giuliani, Z. Matheson, W. Nazarewicz, E. Olsen, P.-G. Reinhard, J. Sadhukhan, B. Schuetrumpf, N. Schunck, and P. Schwerdtfeger, Colloquium: Superheavy elements: Oganesson and beyond, Rev. Mod. Phys. 91, 011001 (2019).
  3. N. V. Antonenko, E. A. Cherepanov, A. K. Nasirov, V. P. Permjakov, and V. V. Volkov, Compound nucleus formation in reactions between massive nuclei: Fusion barrier, Phys. Rev. C 51, 2635 (1995).
  4. G. G. Adamian, N. V. Antonenko, and W. Scheid, Isotopic dependence of fusion cross sections in reactions with heavy nuclei, Nucl. Phys. A 678, 24 (2000).
  5. B. M. Kayumov, O. K. Ganiev, A. K. Nasirov, and G. A. Yuldasheva, Analysis of the fusion mechanism in the synthesis of superheavy element 119 via the Cr54+Am243 reaction, Phys. Rev. C 105, 014618 (2022).
  6. A. Nasirov and B. Kayumov, Optimal colliding energy for the synthesis of a superheavy element with Z=119, Phys. Rev. C 109, 024613 (2024).
  7. B. Kayumov, Investigation of the formation of superheavy elements with atomic numbers 116 and 120 through Ti50-induced reactions, Phys. Rev. C 111, 054619 (2025).
  8. G. G. Adamian, N. V. Antonenko, R. V. Jolos, S. P. Ivanova, and O. I. Melnikova, Effective nucleus-nucleus potential for calculation of potential energy of a dinuclear system, Int. J. Mod. Phys. E 5, 191 (1996).
  9. A. Nasirov, A. Fukushima, Y. Toyoshima, Y. Aritomo, A. Muminov, S. Kalandarov, and R. Utamuratov, The role of orientation of nucleus symmetry axis in fusion dynamics, Nucl. Phys. A 759, 342 (2005).
  10. V. Y. Denisov and W. Nörenberg, Entrance channel potentials in the synthesis of the heaviest nuclei, Eur. Phys. J. A 15, 375 (2002).
  11. G. R. Satchler and W. G. Love, Folding model potentials from realistic interactions for heavy-ion scattering, Phys. Rep. 55, 183 (1979).
  12. D. T. Khoa and G. R. Satchler, Generalized folding model for elastic and inelastic nucleus–nucleus scattering using realistic density dependent nucleon–nucleon interaction, Nucl. Phys. A 668, 3 (2000).
  13. C. Simenel and A. S. Umar, Heavy-ion collisions and fission dynamics with the time-dependent Hartree–Fock theory and its extensions, Prog. Part. Nucl. Phys. 103, 19 (2018).
  14. C. Simenel, Nuclear quantum many-body dynamics, Eur. Phys. J. A 48, 152 (2012).
  15. A. S. Umar and V. E. Oberacker, Heavy-ion interaction potential deduced from density-constrained time-dependent Hartree-Fock calculation, Phys. Rev. C 74, 021601(R) (2006).
  16. K. Washiyama and D. Lacroix, Energy dependence of the nucleus-nucleus potential close to the Coulomb barrier, Phys. Rev. C 78, 024610 (2008).
  17. A. J. Baltz, N. K. Glendenning, S. K. Kauff´mann, and K. Pruess, Long range absorption and other optical-model effects from strong inelastic coupling, Nucl. Phys. A 327, 221 (1979).
  18. K. Alder and A. Winther, Electromagnetic Excitation (North-Holland, Amsterdam, 1975).
  19. S. Ćwiok, J. Dudek, W. Nazarewicz, J. Skalski, and T. Werner, Single-particle energies, wave functions, quadrupole moments and g-factors in an axially deformed Woods–Saxon potential with applications to the two-centre-type nuclear problems, Comput. Phys. Commun. 46, 379 (1987).
  20. A. B. Migdal, Theory of Finite Fermi Systems and Applications to Atomic Nuclei, 2nd ed. (Nauka, Moscow, 1983).
  21. P. Ring and P. Schuck, The Nuclear Many-Body Problem (Springer Berlin Heidelberg, Berlin, 1980).
  22. I. Angeli and K. P. Marinova, Table of experimental nuclear ground state charge radii: An update, At. Data Nucl. Data Tables 99, 69 (2013).
  23. H. de Vries, C. W. de Jager, and C. de Vries, Nuclear charge-density-distribution parameters from elastic electron scattering, At. Data Nucl. Data Tables 36, 495 (1987).
  24. M. Wang, W. J. Huang, F. G. Kondev, G. Audi, and S. Naimi, The AME 2020 atomic mass evaluation (II). Tables, graphs and references, Chin. Phys. C 45, 030003 (2021).
  25. D. Adhikari, H. Albataineh, D. Androic, K. Aniol, D. S. Armstrong, T. Averett, C. Ayerbe Gayoso, S. Barcus, V. Bellini, R. S. Beminiwattha, J. F. Benesch, H. Bhatt, D. Bhatta Pathak, D. Bhetuwal, B. Blaikie, Q. Campagna, A. Camsonne, G. D. Cates, Y. Chen, C. Clarke, et al., Accurate determination of the neutron skin thickness of Pb208 through parity-violation in electron scattering, Phys. Rev. Lett. 126, 172502 (2021).
  26. S. Raman, C. W. Nestor Jr., and P. Tikkanen, Transition probability from the ground to the first-excited 2+ state of even–even nuclides, At. Data Nucl. Data Tables 78, 1 (2001).
  27. P. Möller, J. R. Nix, W. D. Myers, and W. J. Swiatecki, Nuclear ground-state masses and deformations, At. Data Nucl. Data Tables 59, 185 (1995).
  28. A. Tamii, I. Poltoratska, P. von Neumann-Cosel, Y. Fujita, T. Adachi, C. A. Bertulani, J. Carter, M. Dozono, H. Fujita, K. Fujita, K. Hatanaka, D. Ishikawa, M. Itoh, T. Kawabata, Y. Kalmykov, A. M. Krumbholz, E. Litvinova, H. Matsubara, K. Nakanishi, R. Neveling, et al., Complete electric dipole response and the neutron skin in Pb208, Phys. Rev. Lett. 107, 062502 (2011).
  29. R. W. Fearick, P. von Neumann-Cosel, S. Bacca, J. Birkhan, F. Bonaiti, I. Brandherm, G. Hagen, H. Matsubara, W. Nazarewicz, N. Pietralla, V. Y. Ponomarev, P.-G. Reinhard, X. Roca-Maza, A. Richter, A. Schwenk, J. Simonis, and A. Tamii, Electric dipole polarizability of Ca40, Phys. Rev. Res. 5, L022044 (2023).
  30. G. G. Adamian, R. V. Jolos, A. K. Nasirov, and A. I. Muminov, Friction coefficient for deep-inelastic heavy-ion collisions, Phys. Rev. C 56, 373 (1997).
  31. J. Randrup and W. J. Swiatecki, Dissipative resistance against changes in the mass asymmetry degree of freedom in nuclear dynamics: The completed wall-and-window formula, Nucl. Phys. A 429, 105 (1984).
  32. A. K. Nasirov, A. R. Yusupov, and B. M. Kayumov, Small cross section of the synthesis of darmstadtium in the Ca48+Th232 reaction, Phys. Rev. C 110, 014618 (2024).

Outline

Information

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation