Isomeric states of fission fragments explored via Penning trap mass spectrometry at IGISOL

The masses of ^84Br, ^105Mo, ^115,119,121Pd, ^122Ag, ^127,129In, ^132Sb and their respective isomeric states have been measured with the JYFLTRAP Penning trap mass spectrometer using the phase-imaging ion-cyclotron-resonance technique. The excitation energies of the isomeric states in ^132Sb and ^119Pd were experimentally determined for the first time, while for ^84Br, ^115Pd and ^127,129In, the precision of the mass values was substantially improved. In ^105Mo and ^121Pd there were no signs of a long-lived isomeric state. The ground-state measurements of ^119Pd and ^122Ag indicated that both are significantly more bound than the literature values. For ^122Ag, there was no indication of a proposed third long-lived state. The results for the N=49 nucleus ^84Br and isomers close to doubly magic ^132Sn have been compared to the shell-model, proton-neutron quasi-particle random-phase approximation (pnQRPA) and the microscopic quasiparticle-phonon model (MQPM) calculations.