Nuclear charge radii of silicon isotopes

The nuclear charge radius of ${}^{32}$Si was determined using collinear laser spectroscopy. The experimental result was confronted with ab initio nuclear lattice effective field theory, valence-space in-medium similarity renormalization group, and mean field calculations, highlighting important achievements and challenges of modern many-body methods. The charge radius of ${}^{32}$Si completes the radii of the mirror pair ${}^{32}$Ar - ${}^{32}$Si, whose difference was correlated to the slope $L$ of the symmetry energy in the nuclear equation of state. Our result suggests $L\le 60$,MeV, which agrees with complementary observables.