MULTI-QUASIPARTICLE ISOMERS INVOLVING PROTON-PARTICLE AND NEUTRON-HOLE CONFIGURATIONS IN 131I AND 133I
Abstract
The nuclei 131I and 133I have been populated in multi-nucleon transfer reactions between 136Xe ions and various targets, and their structure 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 131I, as well as nanosecond isomers with Jπ = 23/2+ in both isotopes. A T1/2 = 25(3) ns isomer at 4308 keV in 131I 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 
configuration in 130Te, responsible for the 15- isomer in that nucleus. The observed level properties are compared with predictions of a shell-model calculation.
