Fig. 2. Comparison of experimental mean-square charge radii data with different nuclear model predictions.

a, Experimental results of δ⟨r²⟩ of fermium isotopes as a function of N relative to ²⁵⁰Fm (red) and of nobelium isotopes relative to ²⁵⁴No (blue). The error bars show statistical uncertainties (one standard deviation) and the red shaded bands represent systematic uncertainties in the prediction of the atomic parameters (Methods). The observed smooth trend along the isotopic chain is independent of the atomic parameters as their uncertainty is only of a systematic nature, thus affecting all extracted δ⟨r²⟩ in the same manner. Predictions of the spherical droplet model are shown with dashed lines for comparison with the experimental data. b,c, δ⟨r²⟩ for fermium (b) and nobelium (c) predicted by five theoretical models relative to the droplet-model (DM) reference. Experimental data (red and blue solid symbols) are compared with predictions of different models.

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