Fine-structure constant sensitivity of the Th-229 nuclear clock transition

Kjeld Beeks (), Georgy A. Kazakov, Fabian Schaden, Ira Morawetz, Luca Toscani De Col, Thomas Riebner, Michael Bartokos, Tomas Sikorsky, Thorsten Schumm (), Chuankun Zhang, Tian Ooi, Jacob S. Higgins, Jack F. Doyle, Jun Ye and Marianna S. Safronova
Additional contact information
Kjeld Beeks: Vienna center for Quantum Science and Technology, TU Wien
Georgy A. Kazakov: Vienna center for Quantum Science and Technology, TU Wien
Fabian Schaden: Vienna center for Quantum Science and Technology, TU Wien
Ira Morawetz: Vienna center for Quantum Science and Technology, TU Wien
Luca Toscani De Col: Vienna center for Quantum Science and Technology, TU Wien
Thomas Riebner: Vienna center for Quantum Science and Technology, TU Wien
Michael Bartokos: Vienna center for Quantum Science and Technology, TU Wien
Tomas Sikorsky: Vienna center for Quantum Science and Technology, TU Wien
Thorsten Schumm: Vienna center for Quantum Science and Technology, TU Wien
Chuankun Zhang: Department of Physics
Tian Ooi: Department of Physics
Jacob S. Higgins: Department of Physics
Jack F. Doyle: Department of Physics
Jun Ye: Department of Physics
Marianna S. Safronova: University of Delaware

Nature Communications, 2025, vol. 16, issue 1, 1-6

Abstract: Abstract Nuclear laser spectroscopy at the 10−12 precision level (Nature 633.8028 (2024): 63–70) determined the fractional change in the nuclear quadrupole moment of 229Th upon excitation, ΔQ0/Q0 = 1.791(2)%. Such high-accuracy nuclear parameters enable stringent tests and refinement of 229Th nuclear models. Using a semi-classical prolate-spheroid model, we quantify the transition frequency’s sensitivity to fine-structure constant variations as K = 5900(2300), with uncertainty dominated by the measured charge-radius change Δ〈r2〉. This supports the predicted higher α-sensitivity of nuclear clocks over atomic clocks, important for new-physics searches. We find ΔQ0 strongly dependent on nuclear volume, challenging the constant-volume approximation. The deviation between measured and predicted ΔQ0/Q0 underlines the need for improved modeling and measurement of additional nuclear parameters. We explicitly assess the octupole contribution to α-sensitivity.

Date: 2025
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/s41467-025-64191-7 Abstract (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:natcom:v:16:y:2025:i:1:d:10.1038_s41467-025-64191-7

Ordering information: This journal article can be ordered from
https://www.nature.com/ncomms/

DOI: 10.1038/s41467-025-64191-7

Access Statistics for this article

Nature Communications is currently edited by Nathalie Le Bot, Enda Bergin and Fiona Gillespie

More articles in Nature Communications from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().