image: For the ²²C three-body system (²⁰C core + two valence neutrons), this schematic outlines three sets of Jacobi coordinate descriptions, forming the fundamental framework for wave function decomposition and interaction calculation via the three-body Faddeev method in this study.
Credit: Yi-Le Fan
Exploring the Properties of ²²C
As the heaviest carbon isotope located at the neutron dripline, ²²C is classified as a Borromean nucleus and a candidate for a two-neutron halo configuration. Previously, there were uncertainties regarding its two-neutron separation energy and matter radius, which limited the depth of understanding of its weak nuclear binding properties.
“²²C serves as an important object for studying nuclear forces under extreme conditions,” says corresponding author Professor Yi-Bin Qian from Nanjing University of Science and Technology. “The inconsistencies in previous data have posed challenges to fully grasping the relevant properties of this nuclide, and this study attempts to address these uncertainties through an alternative approach.”
Achieving Precision via Experimental Constraints
Drawing on a high-precision experimentally determined matter radius (3.296 ± 0.123 fm), the research team constructed a three-body model (comprising a 20C core and two valence neutrons) and calibrated it using the Faddeev approach. Through the optimization of neutron-core and three-body interaction potentials, the team successfully obtained a more accurate two-neutron separation energy, which is consistent with existing theoretical predictions and experimental limits.
“The experimentally deduced radius provides a reliable constraint for our research,” notes first author Yi-Le Fan. “Correlating the nuclear radius with the separation energy enhances the precision of the measurement results.”
Scientific Significance
This study validates the applicability of the Faddeev method in the research of exotic nuclei and offers valuable insights into universal few-body physical phenomena. The findings are expected to support advancements in fields such as astrophysics and nuclear technology.
“Research on ²²C helps us understand the boundary of nuclear stability,” says Professor Yi-Bin Qian. “Our findings provide a reference for the study of extreme nuclear systems.”
Future Research Directions
The team plans to further investigate the effects of core excitation and deformation in ²²C and similar dripline nuclei, with the aim of refining the theoretical models for neutron-rich nuclear systems.
The complete study is via by DOI: https://doi.org/10.1007/s41365-026-01904-7
Journal
Nuclear Science and Techniques
Method of Research
Computational simulation/modeling
Subject of Research
Not applicable
Article Title
Reexamined mass of <sup>22</sup>C via the constraint from the recently experimental extraction of its radius
Article Publication Date
24-Feb-2026