Possible deformation evolution in theπi13/2structure of171Re

Abstract

The phenomenon of wobbling can only occur for a nuclear shape with stable triaxial deformation. To date, only a few examples of this exotic collective mode have been observed in lutetium and tantalum isotopes. A search for a wobbling sequence was performed in 171 Re to determine if this feature can be observed in Z > 73 nuclei. No evidence was found for wobbling; however, an interaction between the πi 13/2 sequence and another positive-parity band may give an indication on why wobbling may not occur in this nucleus. The level scheme for 171 Re was significantly extended and interpretations for the decay sequences are proposed within the context of the cranked shell model.

High-spin structure of odd-oddRe172

“…As seen in Fig. 3(b), the alignment of this band is slightly higher than that observed in the πh 9/2 structure of 171 Re [4], and this is consistent with the πh 9/2 ν(f 7/2 /h 9/2 ) configuration assignment, as ∼1 of alignment is typically associated with the f 7/2 /h 9/2 quasineutron.…”

“…A normalized angular-correlation ratio (see Ref. [4] for details) of R ang = 0.6(1) is consistent with the 283-keV line linking bands 4 and 3 being of dipole character. Thus, the lowest observed state has been assigned spin (17).…”

“…9 in Ref. [4]) do not predict any other neutron or proton crossing near this frequency. Therefore, this may correspond to an unpaired crossing with another band.…”

“…The experimental details and analysis procedures are presented in Ref. [4]. Many of the new transitions were too weak to perform reliable angular correlation measurements.…”