Learning Nuclear Structure with AI: Radii and Collectivity
Abstract
Low-energy nuclear structure is encoded in a broad body of experimental information across the chart of nuclides. Learning how this information is organized across observables and nuclei can provide a data-driven empirical baseline for theoretical extrapolations and experimental design. Here, we develop held-out ensembles based on NuCLR (Nuclear Co-Learned Representations), a multi-task model of nuclear data, to study charge radii and electric-quadrupole transition strengths. Out-of-fold (OOF) validation shows that shared representation improves performance over single-task learning, yielding a charge-radius RMS deviation of 0.0147 fm and a B(E2) RMS deviation of 0.192 e2b2 across hundreds of nuclides, competitive with state-of-the-art nuclear models. Our error bars estimate the expected prediction accuracy across the nuclear chart, highlighting regions where new data would encode information beyond the learned patterns. NuCLR thus serves as a data-driven surveyor of nuclear structure and a step toward a shared, multi-observable foundation model of the nuclear chart.
Related
- Nuclear moments, charge radii, and magnetization distribution parameters of Ag isotopes from laser spectroscopy and \textit{ab initio} electronic-structure calculations
- Probing collectivity in nuclear binding energies from the viewpoint of the F-spin formalism
- Ab Initio Emergence and Collapse of Nuclear Collectivity near N = Z = 40
- Collapse of Nuclear Collectivity along the N = Z Line
- Nuclear Charge Radii from Precision Bound-Electron g-Factor Measurements
BibTeX
@misc{giacalone2026learning,
title = {{Learning Nuclear Structure with AI: Radii and Collectivity}},
author = {Giuliano Giacalone and Sokratis Trifinopoulos and Mike Williams},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.17838},
eprint = {2609.17838},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.17838},
}
RIS
TY - UNPB
TI - Learning Nuclear Structure with AI: Radii and Collectivity
AU - Giuliano Giacalone
AU - Sokratis Trifinopoulos
AU - Mike Williams
PY - 2026
DA - 2026/09/15
PB - arXiv
DO - 10.48550/arxiv.2609.17838
UR - https://arxiv.org/abs/2609.17838
AB - Low-energy nuclear structure is encoded in a broad body of experimental information across the chart of nuclides. Learning how this information is organized across observables and nuclei can provide a data-driven empirical baseline for theoretical extrapolations and experimental design. Here, we develop held-out ensembles based on NuCLR (Nuclear Co-Learned Representations), a multi-task model of nuclear data, to study charge radii and electric-quadrupole transition strengths. Out-of-fold (OOF) validation shows that shared representation improves performance over single-task learning, yielding a charge-radius RMS deviation of 0.0147 fm and a B(E2) RMS deviation of 0.192 e^2b^2 across hundreds of nuclides, competitive with state-of-the-art nuclear models. Our error bars estimate the expected prediction accuracy across the nuclear chart, highlighting regions where new data would encode information beyond the learned patterns. NuCLR thus serves as a data-driven surveyor of nuclear structure and a step toward a shared, multi-observable foundation model of the nuclear chart.
ER -