Abstract
We measure isotope shifts for five isotopes with zero nuclear spin on two narrow optical quadrupole transitions , with an accuracy of . The corresponding King plot shows a deviation from linearity at the uncertainty level. Such a nonlinearity can indicate physics beyond the Standard Model (SM) in the form of a new bosonic force carrier, or arise from higher-order nuclear effects within the SM. We identify the quadratic field shift as a possible nuclear contributor to the nonlinearity at the observed scale, and show how the nonlinearity pattern can be used in future, more accurate measurements to separate a new-boson signal from nuclear effects.
- Received 23 April 2020
- Accepted 27 July 2020
DOI:https://doi.org/10.1103/PhysRevLett.125.123002
© 2020 American Physical Society
Physics Subject Headings (PhySH)
synopsis
Hints of Dark Bosons
Published 15 September 2020
A signal predicted for a type of dark matter appears in the spectra of ytterbium isotopes.
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