Interpretation of the high spin states inLu161: A paired and unpaired study

Abstract

A paired cranked Nilsson-Strutinsky-Bogoliubov (CNSB) model is presented, which employs the same method to calculate the liquid-drop energy and moment of inertia as the unpaired cranked Nilsson-Strutinsky (CNS) model. In the CNSB model, the energy minimization is carried out in the mesh of pairing gaps and Fermi levels λ as well as deformation parameters. The high spin states in 161 Lu are then investigated with the CNSB and CNS models. The terminating structure shows a striking similarity with these two models. Combining the CNSB and CNS models, a complete understanding of high spin structures, including the normal deformed (ND) and triaxial strongly deformed (TSD) bands and observed side bands in 161 Lu, is achieved. It appears that the only important paired crossings are the first i 13/2 neutron crossing and the first h 11/2 proton crossing. For the description of the unpaired high spin crossings, it is important to be able to distinguish between the pseudospin partners in the proton N = 4 shell, (d 5/2 ,g 7/2 ) and (d 3/2 ,s 1/2 ). The yrast bands are predicted to terminate, which explains the structure of a TSD-like band X2. A band crossing at I ≈ 36.5 for the TSD band in 161 Lu, unique within the chain of even-N Lu isotopes, is well described by the CNSB model.

High-spin terminating states in theN=88Ho155andRees1, Paul2, Simpson3 et al. 2015Phys. Rev. C6180View full textAdd to dashboardCite

“…Thus, the general features of the differences in the lower panel comes out as expected. The pairing energy will continuously become larger with decreasing spin values as has been verified in explicit calculations on 161 Lu [47]. Thus, with pairing included, the differences in Fig.…”

Multiple triaxial bands inNd138

“…In addition to the unpaired CNS calculations, we also carried out calculations in the CNSB formalism with pairing included [29,32]. By varying the total energy with respect to the pairing gaps and Fermi levels, a self-consistent solution of the Hamiltonian with the monopole pairing is achieved by the CNSB model.…”

Observation of high-spin bands with large moments of inertia inXe124

“…13 and experiment are as expected; they exhibit a small down-slope with increasing spin as anticipated when pairing is not included, see; e.g., Refs. [33,34]. Furthermore, the signature degeneracy of bands b3 and b6 is well described at low spin by the fourth h 11/2 orbital.…”