Evidence for shape coexistence in186Pt

Abstract

High-spin states in 186pt have been populated by the 188Os (e, 6n) reaction and were investigated with the OSIRIS spectrometer. A shape coexistence at high spins was established in the nucleus 186pt, which lies on the border between light prolate and heavy oblate Pt nuclei. Two bands corresponding to predominantly prolate shapes and one band of predominantly oblate shape have been observed. For prolate shapes a (7rh9/2) 2 alignment and for oblate shapes a(vi13/2) 2 alignment has been found.

Shape coexistence at high spin in187Au

“…The zcia3/z band (noted 4) experiences a strong alignment (A i-~ 7 h) at h co -~ 0.23 MeV, while for the zc h9/2 band (noted 1) the gain in alignment is weak and progressive. Starting from the same data and arguing of blocking effects, Hebbinghaus et al [23] conclude that the alignment of the 7~i13/2 band in 187Au is totally due to the alignment of a pair of rc h9/2 protons.…”

“…7a where Fig. 1 the kinematic moment of inertia .3 (1), extracted from the slopes of the curves, for the hg/2 and i13/z bands are similar to that of 186pt [23]. Band 5 is built on the state at 444 keV and behaves like a prolate band.…”

Delayed backbending in theπh9∕2band ofIr187Danchev1, Balabanski2, Yigitoglu3 et al. 2003Phys. Rev. C4060View full textAdd to dashboardCite

“…The origin of the band crossings observed in the N Ϸ106 nuclei is still debated, despite the fact that many studies on the high-spin structure of different isotopes have been carried out in this region [1][2][3][4][5][6][7][8][9][10][11]. To explain the first crossing in these nuclei, investigators have invoked the rotational alignment of a pair of both h 9/2 quasiprotons and i 13/2 quasineutrons.…”

“…To explain the first crossing in these nuclei, investigators have invoked the rotational alignment of a pair of both h 9/2 quasiprotons and i 13/2 quasineutrons. References [3][4][5][6][7] provide arguments in support of the alignment of a h 9/2 pair below ប=0.30 MeV. On the other hand, it is quite difficult to theoretically reproduce this h 9/2 crossing at such a low frequency using a standard set of Nilsson-model parameters, as discussed in Ref.…”

Triaxial deformation and nuclear shape transition in192Au

“…By adding more and more neutrons, the shape becomes oblate with the quadrupole deformation parameter β 2 [1] taking values β 2 ≤ 0.15 [2][3][4]. A prolate-oblate shape change has been discussed for these nuclei [5][6][7][8][9][10][11]. Recently, the nuclei in this prolate-oblate transition region were described by a potential with similar energy minima corresponding to prolate and oblate shapes [12,13].…”