Spectroscopy of exotic 121, 123, 125Ag produced in fragmentation reactions

Excited states in the neutron-rich 121, 123, 125Ag were studied via the fragmentation of a 136Xe beam at 120MeV/nucleon in a thick 9Be target. The levels in 121Ag were populated in the \( \beta\) decay of 121Pd while those assigned to 123, 125Ag were identified via isomer spectroscopy. The transitions identified in 121Ag are consistent with the \( \gamma\) -rays reported in 117, 119Ag . The newly observed transitions were placed in the level schemes of 123, 125Ag based on the analysis of \( \gamma\) -\( \gamma\) coincidences and the systematics. We attribute the onset of isomerism in the 123, 125Ag isotopes to the drop in energy of the negative-parity levels similar to the 5- state in the even-even Cd cores. The proposed level scheme for 125Ag is well described by the NuShellX shell model calculations.