X(5) critical-point symmetries in 138Gd
Procter, M. G., Cullen, D., Ruotsalainen, P., Braunroth, T., Dewald, A., Fransen, C., . . . Xu, F. R. (2012). X(5) critical-point symmetries in 138Gd. In Rutherford Centennial Conference on Nuclear Physics 8–12 August 2011, Manchester, UK (pp. 012062). Journal of Physics: Conference Series (381). Bristol: Institute of Physics. doi:10.1088/1742-6596/381/1/012062
Published inJournal of Physics: Conference Series;381
Rice, S. |
Shi, Y. |
© Published under licence by IOP Publishing Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY) licence.
The lifetimes of low-lying transitions in 138Gd have been measured using the recoil-distance Doppler-shift technique. The resultant reduced transition probabilities have been compared to X(5) critical-point calculations to assess the potential ‘phase-transitional’ behaviour of 138Gd. The X(5) symmetry describes the first order ‘phase transition’ between sphericity, U(5) and an axially deformed nuclear shape, SU(3). Although a high degree of correspondence is observed between the experimental and theoretical excitation energies, the large uncertainties of the experimental B(E2) values cannot preclude contributions from either vibrational or rotational modes of excitation. In order to further examine the nature of low-lying states in 138Gd, ongoing work is aiming to derive solutions to the Bohr Hamiltonian using a more general potential that is not restricted to the X(5) critical point. These results, in parallel to more extensive IBM-1 calculations, will eventually be compared to the experimental results to more accurately locate 138Gd along the U(5) - SU(3) arm of the structure triangle. ...