Pb 208 Nuclear Charge Radius Revisited: Closing the Fine-Structure-Anomaly Gap
Year: 2025
Type: article
Abstract: A comprehensive reevaluation of the root-mean-square nuclear charge radius is presented for the doubly magic ^{208}Pb extracted from muonic spectroscopy measurements. By integrating rigorous theoretical quantum electrodynamics calculations, state-of-the-art numerical methods, and a systematic reanalysis of the uncertainties, we reduced the long-standing muonic fine-structure anomaly and improved the goodness of fit by a factor of 20. The resulting value of 5.5062(5) fm for a Fermi distribution is fairly consistent with the previously reported muonic spectroscopy value, and 3 standard deviations larger than the commonly used compilation data, which indicates that the current value and its uncertainty could be significantly underestimated. Attributing the remaining discrepancy to theory errors which cannot be rigorously calculated, we suggest the rms charge radius with reduced model dependence to be 5.5062(17) fm. This Letter sets an improved benchmark for charge radius extraction in heavy nuclei and paves a path for systematic reevaluations across the nuclear chart.
Source: Physical Review Letters
DOI: 10.1103/h3xz-xdxr
Institution: Max Planck Institute for Nuclear Physics
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,750
Funder: Deutsche Forschungsgemeinschaft
OpenAlex ID: W4415225201