| 1. |
- Neusser, A, et al.
(författare)
-
Superdeformed band at very high spin in Nd-140
- 2004
-
Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 70:6
-
Tidskriftsartikel (refereegranskat)abstract
- A new high-spin superdeformed band has been discovered in Nd-140(60)80. It was populated in the Zr-96(Ca-48,4n) reaction and investigated using the EUROBALL gamma-ray spectrometer array. The band is observed in the approximate spin range of I=36 to 66. It is associated with shell gaps around Z=60 and at N=80 at large deformation. These gaps produce a pronounced minimum in the calculated total Routhian surfaces at a quadrupole deformation of epsilon(2)=0.45. The new band which lies between the high-deformation bands in the Aapproximate to130 region and the superdeformed bands in Aapproximate to150 nuclei provides insight into the development of the deformation between these two regions. Two possible configurations are suggested involving four neutrons of i(13/2) origin (nu6(4)) and either six protons of h(11/2)/h(9/2) origin (pi5(6)) or five protons of h(11/2)/h(9/2) and one of i(13/2) origin (pi5(5)6(1)).
|
|
| 2. |
- Wilson, A. N., et al.
(författare)
-
Magnetic dipole bands in 190Hg : First evidence of excitations across the Z = 82 sub-shell in Hg nuclei
- 2001
-
Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 505:1-4, s. 6-14
-
Tidskriftsartikel (refereegranskat)abstract
- An experiment aimed at studying high-spin states in 190Hg was performed with the Eurogam II array. The data have revealed the presence of cascades of magnetic dipole transitions with some unexpected properties. Unlike the MI bands previously observed in the heavier Hg isotopes, these structures have extremely large B(M1)/B(E2) ratios, The observation of a third dipole band with much lower B(M1)/B(E2) values in the same spin/excitation energy regime suggests that the bands may represent configurations occurring in different minima in the potential energy surface. Configuration-dependent Cranked Nilsson-Strutinsky calculations predict the presence of a minimum in the nuclear potential energy surface at a deformation of ε ≅ 0.2, γ ≅ -90°, occurring when a proton is excited across the Z = 82 shell-gap into an h9/2 orbital. It is suggested that the bands exhibiting anomalously large B(M1)/B(E2) ratios may be associated with this minimum.
|
|
| 3. |
- Gueorguieva, E., et al.
(författare)
-
High-spin states in Au-191 : Evidence for triaxial shape?
- 2003
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 68:5, s. 543081-5430814
-
Tidskriftsartikel (refereegranskat)abstract
- The level scheme of Au-191 was considerably extended to high spin using gamma spectroscopy with the Eurogam-II array and internal conversion measurements with the Orsay electron spectrometer. Several bands that appear as strongly coupled were associated with low- Omega configurations in Au-191 . Using total routhian surface and cranked shell model calculations it was shown that these bands have a rotation-aligned nature and are most likely generated by the nonaxiallity of the nucleus induced by the odd proton. The predictions for the presence of such bands in Au-191 and in the oblate nuclei in the Pt-Au-Hg region found excellent agreement with the experimental data, as well as the predictions for their alignments and band-crossing frequencies in Au-191 .
|
|
| 4. |
- Gueorguieva, E., et al.
(författare)
-
Sets of rotation-aligned bands indicating nonaxiality in Au-190
- 2004
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 69:4, s. 044320-
-
Tidskriftsartikel (refereegranskat)abstract
- The level scheme of Au-190 was extended up to high spin using gamma spectroscopy with the Eurogam-II array and internal conversion measurements with the electron- gamma spectrometer of Orsay. Several sets of rotation-aligned bands were found and associated with high- j, low- K configurations. According to the total Routhian surface and cranked shell model calculations these bands are caused by the nonaxiality of the nuclear deformation (gammaless than or equal to-70degrees). Furthermore, very good agreement was obtained between the experimental data and the theoretical predictions for the properties of these bands, such as alignments, band-crossing frequencies, and signature inversion, thus supporting the suggested nonaxial shapes.
|
|
