Ground-state properties of finite nuclei in relativistic Hartree-Bogoliubov theory with an improved quark mass density-dependent model

TL;DR

The study develops a subnucleon-based relativistic Hartree-Bogoliubov framework (IQMDD+RHB) incorporating quark–meson coupling within the IQMDD model and introduces the IQMDD3 parameterization fitted to binding energies and charge radii. Applying this approach to 868 even-even nuclei with $8\leq Z\leq118$, the authors examine binding energies, charge radii, quadrupole deformations, two-nucleon separation energies, two-nucleon shell gaps, and $\alpha$-decay energies, achieving competitive accuracy against established EDFs. Key results include $\sigma_{B/A}\approx0.034$ MeV and $\sigma_B\approx2.89$ MeV for binding energies, $\sigma_{R_c}\approx0.022$ fm for charge radii, and a predicted $R_{np}(^{208}$Pb) around $0.24$ fm with symmetry energy $S\approx36$ MeV and slope $L\approx100$ MeV; the model also captures major-shell and subshell features and neutron/proton separation-energy trends, albeit with some region-dependent deviations. The work demonstrates the viability of integrating subnucleonic degrees of freedom into a self-consistent RHB framework for global nuclear structure studies and points to future extensions toward drip-line nuclei.

Abstract

A relativistic Hartree-Bogoliubov (RHB) model based on quark-meson coupling is developed, with a new parametrization derived from experimental observables. Using this model, we systematically investigate the ground-state properties of even-even nuclei spanning $8\leq Z\leq118$, including binding energies, quadrupole deformations, root-mean-square (rms) charge radii, two-nucleon separation energies, two-nucleon shell gaps, and $α$-decay energies. Comparisons with available experimental data demonstrate that this subnucleon-based RHB model reliably describes the ground-state properties of finite nuclei.

Figures (8)

• Figure 1: Differences in total binding energy between the calculations and experimental data for even-even nuclei using the IQMDD3 and IQMDD-2*. To guide the eye, the dashed frames correspond to the positions of the magic numbers 8, 20, 28, 50, 82, and 126.
• Figure 2: Quadrupole deformation parameters for even-even nuclei with proton numbers $8\leq Z\leq118$, calculated using the RHB approach with the IQMDD3 interaction.
• Figure 3: Discrepancies between IQMDD3+RHB calculations and experimental data for even-even nuclei with measured charge radii.
• Figure 4: Left: The two-neutron separation energies of even-even nuclei calculated by IQMDD3. Right: The deviation between the theoretical and experimental values of the two-neutron separation energies.
• Figure 5: