A concentration of dipole strength at energies below the giant dipole resonance was observed in neutron‐rich nuclei around 132Sn in an experiment using the FRS‐LAND setup. This so‐called “pygmy” dipole strength can be related to the parameters of the symmetry energy and to the neutron skin thickness on the grounds of a relativistic quasiparticle random‐phase approximation. Using this ansatz and the experimental findings for 130Sn and 132Sn, we derive a value of the symmetry energy pressure of 0 = 2.2±0.5 MeV/fm3. Neutron skin thicknesses of RnRp = 0.23±0.03 fm and 0.24±0.03 fm for 130Sn and 132Sn, respectively, have been determined. Preliminary results on 68Ni from a similar experiment using an improved setup indicate an enhanced cross section at low energies, while the results for 58Ni are in accordance with results from photoabsorption measurements.

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