File:PhysRevLett.122.192502.pdf

English: The change in mean-square nuclear charge radii δ⟨r2⟩ along the even-A tin isotopic chain 108−134Sn has been investigated by means of collinear laser spectroscopy at ISOLDE/CERN using the atomic transitions 5p2 1S0→5p6 s1P1 and 5p2 3P0→5p6s 3P1. With the determination of the charge radius of 134Sn and corrected values for some of the neutron-rich isotopes, the evolution of the charge radii across the N=82 shell closure is established. A clear kink at the doubly magic 132Sn is revealed, similar to what has been observed at N=82 in other isotopic chains with larger proton numbers, and at the N=126 shell closure in doubly magic 208Pb. While most standard nuclear density functional calculations struggle with a consistent explanation of these discontinuities, we demonstrate that a recently developed Fayans energy density functional provides a coherent description of the kinks at both doubly magic nuclei, 132Sn and 208Pb, without sacrificing the overall performance. A multiple correlation analysis leads to the conclusion that both kinks are related to pairing and surface effects.