Observation of a μs isomer in In8549134: Proton-neutron coupling “southeast” of Sn8250132

We report on the observation of a microsecond isomeric state in the single-proton-hole, three-neutron-particlenucleus134In. The nuclei of interest were produced by in-flight fission of a238U beam at the Radioactive IsotopeBeam Factory at RIKEN. The isomer depopulates through a?ray of energy 56.7(1) keV and with a half-life ofT1/2=3.5(4)µs. Based on the comparison with shell-model calculations, we interpret the isomer as theIp=5-member of thep0g-19/2??1f37/2multiplet, decaying to theIp=7-ground state with a reduced-transitionprobability ofB(E2; 5-?7-)=0.53(6) W.u.Observation of this isomer, and lack of evidence in the currentwork for aIp=5-isomer decay in132In, provides a benchmark of the proton-neutron interaction in the regionof the nuclear chart “southeast” of132Sn, where experimental information on excited states is sparse.