Isotope shift as a probe of new physics

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Overview

Bosonization, in which a fermionic model in 1 + 1 dimensions is transformed to an equivalent bosonic model, has been a powerful technique for the analytical study of many models. However, although the bosonized model is usually much simpler than the original model, obtaining the analytical exact solution is still
Isotope shift (IS) in atomic spectra is sensitive to a new interaction between the electron and the neutron.
In the standard model (SM) of particle physics, the finite nuclear mass and size varying from one isotope to another cause the IS.
Since the theoretical calculation of IS is not easy, even in the SM, we introduce a new method to search for the new interaction.
Our method employs a generalization of the King linearity of IS, the generalized IS linearity.
We apply various generalized linearities to recent IS data of Ytterbium (Yb) and illustrate constraints on the new interaction.

References
K. Mikami, MT, Y.Yamamoto, EPJC 77, 896 (2017) K. Ono, MT et al. PRX 12, 021033 (2022)