Experimental study of high-spin band structures in odd-odd 172Re

High-spin states in odd-odd Re-172 have been investigated via the Sm-149 (Al-27,4ngamma) Re-172 reaction through excitation functions, X-gamma and gamma-gamma coincidence measurements. A level scheme consisting of three rotational bands has been identified for the first time, extending the high-spin studies of A 170 odd-odd nuclei to the currently lightest rhenium isotope. The three bands have been assigned to be built on the pih(11/2) circle times nui(13/2), pih(9/2) circle times nui(13/2) and pi1/2(-) [541]circle timesnu1/2(-) [521] configurations according to their rotational properties in quasiparticle alignments, signature splitting, in-band B(M1)/B(E2) ratios, level spacing systematics, band crossing frequencies, as well as the existing knowledge in neighboring nuclei. Low-spin signature inversion has been confirmed in the first two bands due to observation of signature crossing at high-spin states.