Odd-even staggering in the πg9/2vg9/2 band in 72Br

High-spin positive-parity states in 72Br have been studied using the 16O+58Ni reaction. The πg9/2vg9/2 decoupled band in 72Br has been observed up to ∼10 MeV excitation energy and the expected odd-even staggering has been delineated. A larger signature splitting is observed for this band in 72Br than in the same collective structures in the heavier 74,76,78Br. No signature inversion at low spin is observed for this band in 72Br, in contrast to the heavier isotopes, 74,76,78Br, in which signature inversion is observed below ∼10(Latin small letter h with stroke sign). The observations are in general agreement with theoretical models in this mass region which predict no signature inversion for nuclei with less than 39 protons and neutrons.