Multi-quasiparticle isomers involving proton-particle and neutron-hole configurations in I-131 and I-133

The nuclei I-131 and I-133 have been populated in multinucleon transfer reactions between Xe-136 ions and various targets, and their structure has been investigated by time-correlated gamma-ray coincidence spectroscopy and the measurement of gamma-ray angular correlations. A 19/2(-) isomer at 1918 keV, with a half-life of 24(1) mu s, has been identified in I-131, as well as nanosecond isomers with J(pi)=23/2(+) in both isotopes. A T-1/2=25(3) ns isomer at 4308 keV in I-131 is suggested to have J(pi)=(31/2(-),33/2(-)) and is primarily attributed to the coupling of an odd proton in the d(5/2) or g(7/2) orbit with the (pi(2))(0)(+)(nu h(11/2)(-3)d(3/2)(-1))(15)(-) configuration in Te-130 responsible for the 15(-) isomer in that nucleus. The observed level properties are compared with predictions of a shell-model calculation.