Multi-quasiparticle isomers involving proton-particle and neutron-hole configurations in I131 and I133

Abstract

The nuclei I131 and I133 have been populated in multinucleon transfer reactions between Xe136 ions and various targets, and their structure has been investigated by time-correlated γ-ray coincidence spectroscopy and the measurement of γ-ray angular correlations. A 19/2- isomer at 1918 keV, with a half-life of 24(1) μs, has been identified in I131, as well as nanosecond isomers with Jπ=23/2+ in both isotopes. A T1/2=25(3) ns isomer at 4308 keV in I131 is suggested to have Jπ=(31/2-,33/2-) and is primarily attributed to the coupling of an odd proton in the d5/2 or g7/2 orbit with the (π2)0+(νh11/2-3d3/2-1)15- configuration in Te130 responsible for the 15- isomer in that nucleus. The observed level properties are compared with predictions of a shell-model calculation. Show more