Charge radii of calcium isotopes within relativistic configuration-interaction density functional theory

@misc{qu2026charge,
  title = {{Charge radii of calcium isotopes within relativistic configuration-interaction density functional theory}},
  author = {Teng Qu and Bo Li and Yakun Wang},
  howpublished = {arXiv},
  year = {2026},
  month = jul,
  doi = {10.48550/arxiv.2607.08478},
  eprint = {2607.08478},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2607.08478},
}

TY  - UNPB
TI  - Charge radii of calcium isotopes within relativistic configuration-interaction density functional theory
AU  - Teng Qu
AU  - Bo Li
AU  - Yakun Wang
PY  - 2026
DA  - 2026/07/09
PB  - arXiv
DO  - 10.48550/arxiv.2607.08478
UR  - https://arxiv.org/abs/2607.08478
AB  - The charge radii of calcium isotopes are investigated within the framework of relativistic configuration-interaction density functional (ReCD) theory. The ReCD theory microscopically incorporates beyond-mean-field correlations through rotational symmetry restoration and configuration mixing among quasiparticle excited states, and treats even-even and odd-A isotopes on the same footing. It is found that beyond-mean-field correlations significantly soften the potential energy surfaces of calcium isotopes and shift the energy minima from nearly spherical mean-field solutions to deformed shapes. The quadrupole deformation parameters predicted by the ReCD theory show much better agreement with the available experimental data than the mean-field results, supporting the reliability of the calculated potential energy surfaces and highlighting the important role of beyond-mean-field correlations. Owing to the sensitive dependence of charge radii on nuclear deformation, the charge radii obtained within the ReCD framework are generally larger than the mean-field predictions. The nearly identical charge radii of ^40Ca and ^48Ca, as well as the unexpectedly large charge radius of ^52Ca, are well reproduced. Compared with the mean-field calculations, the description of the odd-even staggering is improved, especially for the enhanced charge radii of ^42Ca and ^44Ca. It is also worth noting that secondary local minima appear in the ReCD-based potential energy surfaces of the odd-A calcium isotopes ^41,43,47Ca. The present results suggest that shape mixing between different local minima, which is not fully included in the present calculation, may further improve the description of the pronounced odd-even staggering observed in calcium isotopes.
ER  -