YRAST BRANDS IN I-117 AND XE-116-118 - ANOMALOUS QUASI-PARTICLE ALIGNMENT FREQUENCIES AND BAND TERMINATION

The yrast bands of neutron-deficient I117 and Xe116 have been extended to I∼34Latin small letter h with stroke, and Xe117,118 to I∼46Latin small letter h with stroke, using highfold γ-ray coincidence data collected with the Eurogam II spectrometer. Systematic quasiparticle alignment frequencies are discussed and compared to theoretical cranked Woods-Saxon calculations. The first pair alignment is attributed to h11/2 protons despite theoretical expectations for h11/2 neutron alignment; the neutron alignment appears significantly delayed. At higher spins, the I117 and Xe117 isobars exhibit contrasting forms of band termination. © 1995 The American Physical Society.