Lifetime measurements in low yrast states and spectroscopic peculiarities in 182Os

Lifetimes of the low-lying yrast states 2+, 4+, and 6+ of the unstable nucleus 182Os were measured using digital fast-timing techniques. The lifetimes of the 4+ and 6+ states were determined for the first time. The remeasured value for the lifetime of the 2+1 state was taken into account to evaluate the discrepancy between two inconsistent literature values. The lifetimes and extracted B(E2) values are presented and discussed in terms of collective signatures and transitional phenomena. The B(E2; 4+1 & RARR; 2+1 )/B(E 2; 2+1 & RARR; 0+1 ) ratio of 1.39(7) supports the interpretation of 182Os as a rigid rotor. This value is discussed in the context of these of the neighboring isotopes and isotones and calculations in the framework of the interacting boson model 1. Additionally, competing influences from the near lying collective deformed region, & gamma;-soft rotors, X(5) symmetry, and neighboring regions of shape coexistence in low excitation states are assumed to influence the structure of the nucleus of interest: The trend of the excitation energies of the & gamma;- and K & pi; = 0-bands in the osmium isotopic chain change remarkably at 182Os. This consideration helps to us delimit and understand the structural transitions in the isotopic and isotonic chains that intersect at 182Os.

Automated summary

In this study, the lifetimes of the low-lying yrast states 2+, 4+, and 6+ of the unstable nucleus 182Os were measured using digital fast-timing techniques. The lifetimes of the 4+ and 6+ states were determined for the first time. The discrepancy between two inconsistent literature values was evaluated by taking into account the remeasured value for the lifetime of the 2+1 state.