News on the nuclear structure of neutron-rich nuclei at and beyond N = 28

The nuclear potential and resulting shell structure are well established for the valley of stability, however, dramatic modifications to the familiar ordering of single-particle orbitals in rare isotopes with a large imbalance of proton and neutron numbers have been found: new shell gaps emerge and conventional magic numbers are no longer valid. This article outlines some of the recent in-beam γ-ray spectroscopy measurements at NSCL aimed at shedding light on the evolution of nuclear structure around neutron number N = 28 in neutron-rich Ar and S isotopes. (author)