First observation of rotational structures in Re168

We assigned first rotational sequences to the odd-odd nucleus 168Re. Coincidence relationships of these structures with rhenium x rays confirm the isotopic assignment, while arguments based on the γ-ray multiplicity (K-fold) distributions observed with the new bands lead to the mass assignment. Configurations for the two bands were determined through analysis of the rotational alignments of the structures and a comparison of the experimental B(M1)/B(E2) ratios with theory. Tentative spin assignments are proposed for the πh11/2νi13/2 band, based on energy level systematics for other known sequences in neighboring odd-odd rhenium nuclei, as well as on systematics seen for the signature inversion feature that is well known in this region. Furthermore, the spin assignment for the πh11/2ν(h9/2/f7/2) structure provides additional validation of the proposed spins and configurations for isomers in the 176Au → 172Ir → 168Re α-decay chain.