Nuclear structure at high angular momentum

Superdeformed band with a unique decay pattern: possible evidence for octupole vibration in 190Hg

“…The previously known SD band in ]9°Hg [ 11,14] was observed. With the added sensitivity of GAMMA-SPHERE, it was possible to add a 317.7 keV transition (d) shift of the centroid of the 625 keV peak in the spectrum gated on the excited band; (e) enhancement of transitions in the excited band in a double gate on the 625 keV doublet along with members of the yrast SD band, compared with a similar gate on the 417 keV normally deformed line (see text).…”

“…We report here on the discovery of a new SD band in ;9°Hg with a unique decay pattern: the band feeds directly into the previously known SD band [ 11,14]. Furthermore, the transitions linking the two sets of SD states have also been tentatively identified.…”

“…At the highest frequencies, a sharp rise is noticeable. Such a rise has been qualitatively reproduced in cranked Strutinsky [ 14,20] and cranked Hartree-Fock [21] calculations, and is interpreted as being due to a combination of a dynamic reduction in the pairing correlations as a function of spin and a band crossing between the zero-quasiparticle SD band and a rotation-aligned (j15/2) 2 neutron band. More important for the present discussion is the observation that the excited SD band is characterized by a constant value of ~(2) = 123 ± lh2/MeV (with X2= 3.6 per degree of freedom) which is about 20% larger than those of the other SD bands in the region.…”

Investigation of the use of an α + Xn reaction channel to enhance the population of superdeformed states in193Hg and195Hg

“…Although the intensities of the γ -ray peaks in the 193 Hg superdeformed band are weak, the band's existence was separately confirmed using the interactive analysis program BANDAID [21]. This program uses a two-dimensional grid to facilitate the search for band structures in a γ -ray correlation matrix.…”