Neutron-unbound states in 50Ar and 52Ar were investigated via the (p,2p) proton-knockout reaction using the invariant-mass spectroscopy technique. Two (50Ar) and three (52Ar) distinct, narrow resonances were observed in the vicinity of the neutron separation energy. Based on a comparison with theoretical level schemes and calculated (p,2p) cross sections, tentative spin-parity assignments have been proposed. The good degree of consistency between the predicted level structures and the observed states indicates that the large N = 32 and N = 34 shell gaps inherent in the theoretical calculations accurately describe the nuclear structure in this region. These results provide further support for the robustness of these subshell closures in the neutronrich argon isotopes
QC 20260723