A complete-spectroscopy investigation of low-lying, low-spin states in the one-proton-hole and one-neutron-hole nucleus 206Tl has been performed by using thermal neutron capture and γ-coincidence technique with the FIPPS Ge array at ILL Grenoble. The new experimental results, together with data for the one-proton-particle and one-neutron-particle nucleus 210Bi (taken from a previous study done at ILL in the EXILL campaign), allowed for an extensive comparison with predictions of shell-model calculations performed with realistic interactions. No phenomenological adjustments were introduced in the calculations. In 210Bi, state energies, transition multipolarities and decay branchings agree well with theory for the three well separated multiplets of states which dominate the low-lying excitations. On the contrary, in 206Tl significant discrepancies are observed: in the same energy region, six multiplets were identified, with a significant mixing among them being predicted, as a consequence of the smaller energy separation between the active orbitals. The discrepancies in 206Tl are attributed to the larger uncertainties in the determination of the off-diagonal matrix elements of the realistic shell-model interaction with respect to the calculated diagonal matrix elements, the only ones playing a major role in the case of 210Bi. The work points to the need of more advanced approaches in the construction of the realistic interactions.
Contrasting properties of particle-particle and hole-hole excitations in 206Tl and 210Bi nuclei / N. Cieplicka-Oryńczak, C. Michelagnoli, A. Gargano, B. Fornal, S. Leoni, G. Benzoni, A. Blanc, S. Bottoni, F.C.L. Crespi, Ł.W. Iskra, M. Jentschel, U. Köster, P. Mutti, N. Pietralla, E. Ruiz-Martinez, V. Werner. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - 802(2020 Mar 10).
|Titolo:||Contrasting properties of particle-particle and hole-hole excitations in 206Tl and 210Bi nuclei|
CRESPI, FABIO CELSO LUIGI (Penultimo)
|Parole Chiave:||Branching ratios 206Tl; Comparison with shell-model calculations; Deduced levels and Jπ206Tl; Nuclear structure 206Tl, 210Bi; γγ-coin. 206Tl;|
|Settore Scientifico Disciplinare:||Settore FIS/04 - Fisica Nucleare e Subnucleare|
|Data di pubblicazione:||10-mar-2020|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/j.physletb.2020.135222|
|Appare nelle tipologie:||01 - Articolo su periodico|