Identification Of Sub-Mu S Isomeric States In The Odd-Odd Nucleus( 178)Au

The neutron-deficient gold (Z = 79) isotopes in the vicinity of the neutron midshell N = 104 provide prolific examples of shape coexistence and isomerism at low excitation energy. They can be probed via a number of different experimental techniques. In this study, two new isomeric states with half-lives of 294(7) and 373(9) ns have been observed in the neutron-deficient odd-odd nuclide Au-178 (N = 99) in an experiment at the RITU gas-filled separator at JYFL, Jyvaskyla. This result was achieved due to the use of a segmented planar germanium detector with a high efficiency at low energies. By applying the recoil-decay tagging technique, they were assigned to decay to two different long-lived a-decaying states in Au-178.