Identification of yrast high-Kintrinsic states inOs188

Abstract

The high-spin structure of the Z = 76 nucleus 188 Os has been studied using the incomplete fusion reaction

Triaxial angular momentum projection and configuration mixing calculations with the Gogny force

“…This restriction is one of the major drawbacks of the method because it limits its applicability to systems where triaxiality does not play an important role. However, many exciting experimental and theoretical phenomena are closely related to the triaxial degree of freedom, for instance: the presence of γ-bands in the low lying energy spectra and γ-softness, shape coexistence and shape transitions in transitional regions [13,[15][16][17][18][19][20]; the lowering of fission barriers along the triaxial path [21][22][23]; the influence of triaxial deformation in the ground state for the mass models [24,25]; triaxiality at high spin [26][27][28]; the observation of K-bands and isomeric states in the Os region [29][30][31]; or some other exotic excitation modes such as wobbling motion and chiral bands [32][33][34].…”

New high-spin isomer and quasiparticle-vibration coupling inIr187

“…1(a) of Ref. [19]). Starting from the coincidence spectrum with a gate on this transition, a comprehensive excitation scheme has been established above the isomer reaching up to spin (59/2 − ).…”

“…In addition, charged particles emitted in the p × n, d × n, and t × n reaction channels leading to osmium isotopes (see Refs. [19] and [20]) were detected in the Si ball ISIS consisting of 40 E − E telescopes arranged in the same geometry as the Ge crystals in GASP, namely, in seven rings with θ = 35…”

“…A triaxial rotor model for odd-A nuclei, thus the coupling of the odd nucleon to a triaxially deformed core, was shown to reproduce the properties of this band in a satisfactory way [18,25]. However, it seems somewhat unsatisfactory to employ this model, which is based on rigid triaxial shapes, when a number of different potential energy surface calculations [19,26,[30][31][32][33] consistently indicate γ softness of the eveneven Os core nuclei but do not provide evidence of rigid triaxiality. An alternative way to describe the irregular h 11/2 band is the γ -vibrational (GV) model, in which the odd particle is coupled to the γ vibration of a symmetric rotor [14].…”

Shapes, Softness and Non-Yrast Collectivity in 186W

“…The exceptions in neighboring elements are 178,180 Hf [43,44] and 186,188 Os [45,46]. These cases show distinct patterns that are connected to the underlying physics.…”