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Updated: Sep 24, 2025

Setting Limits on Supersymmetry Using Simplified Models
Published on: November 15, 2013
Evidence of Two-Source King Plot Nonlinearity in Spectroscopic Search for New Boson
Joonseok Hur1, Diana P L Aude Craik1, Ian Counts1
1Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Abstract:
Optical precision spectroscopy of isotope shifts can be used to test for new forces beyond the standard model, and to determine basic properties of atomic nuclei. We measure isotope shifts on the highly forbidden ^{2}S_{1/2}→^{2}F_{7/2} octupole transition of trapped ^{168,170,172,174,176}Yb ions. When combined with previous measurements in Yb^{+} and very recent measurements in Yb, the data reveal a King plot nonlinearity of up to 240σ. The trends exhibited by experimental data are explained by nuclear density functional theory calculations with the Fayans functional. We also find, with 4.3σ confidence, that there is a second distinct source of nonlinearity, and discuss its possible origin.
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