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  • Letter
  • Open Access

Sensitivity of nuclear clocks to new physics

Andrea Caputo1,*, Doron Gazit2,†, Hans-Werner Hammer3,4,‡, Joachim Kopp1,5,§, Gil Paz6,∥, Gilad Perez7,¶, and Konstantin Springmann7,8,**

  • *Contact author: andrea.caputo@cern.ch
  • †Contact author: doron.gazit@mail.huji.ac.il
  • ‡Contact author: Hans-Werner.Hammer@physik.tu-darmstadt.de
  • §Contact author: jkopp@cern.ch
  • ∥Contact author: gilpaz@wayne.edu
  • Contact author: gilad.perez@weizmann.ac.il
  • **Contact author: konstantin.springmann@weizmann.ac.il
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Phys. Rev. C 112, L031302 – Published 11 September, 2025

DOI: https://doi.org/10.1103/l29n-gt5j

Abstract

The recent demonstration of laser excitation of the ≈8eV isomeric state of Th229 is a significant step towards a nuclear clock. The low excitation energy likely results from a cancellation between electromagnetic and strong contributions, which new physics can disrupt. In this Letter, we quantify the enhancement of a nuclear clock's sensitivity to new physics using a geometric model and a novel d-wave halo model of the nucleus that reproduces measured differences between Th229 states. We find likely enhancements of order 104, while a worst case with enhancement ≪1 is unlikely.

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Phys. Rev. C 112, L031302– Published 11 September, 2025
  • Received 20 August 2024
  • Accepted 8 August 2025
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