학술논문
Shape coexistence in the neutron-deficient $^{188}$Hg investigated via lifetime measurements
Document Type
Working Paper
Author
Siciliano, M.; Zanon, I.; Goasduff, A.; John, P. R.; Rodríguez, T. R.; Péru, S.; Deloncle, I.; Libert, J.; Zielińska, M.; Ashad, D.; Bazzacco, D.; Benzoni, G.; Birkenbach, B.; Boso, A.; Braunroth, T.; Cicerchia, M.; Cieplicka-Oryńczak, N.; Colucci, G.; Davide, F.; de Angelis, G.; de Canditiis, B.; Gadea, A.; Gaffney, L. P.; Galtarossa, F.; Gozzelino, A.; Hadyńska-Klȩk, K.; Jaworski, G.; Koseoglou, P.; Lenzi, S. M.; Melon, B.; Menegazzo, R.; Mengoni, D.; Nannini, A.; Napoli, D. R.; Pakarinen, J.; Quero, D.; Rath, P.; Recchia, F.; Rocchini, M.; Testov, D.; Valiente-Dobón, J. J.; Vogt, A.; Wiederhold, J.; Witt, W.
Source
Phys. Rev. C 102, 014318 (2020)
Subject
Language
Abstract
Shape coexistence in the $Z \approx 82$ region has been established in mercury, lead and polonium isotopes. Even-even mercury isotopes with $100 \leq N \leq 106$ present multiple fingerprints of this phenomenon, which seems to be no longer present for $N \geq 110$. According to a number of theoretical calculations, shape coexistence is predicted in the $^{188}$Hg isotope. The $^{188}$Hg nucleus was populated using two different fusion-evaporation reactions with two targets, $^{158}$Gd and $^{160}$Gd, and a beam of $^{34}$S, provided by the Tandem-ALPI accelerators complex at the Laboratori Nazionali di Legnaro. The channels of interest were selected using the information from the Neutron Wall array, while the $\gamma$ rays were detected using the GALILEO $\gamma$-ray array. The lifetimes of the excited states were determined using the Recoil Distance Doppler-Shift method, employing the dedicated GALILEO plunger device. Using the two-bands mixing and rotational models, the deformation of the pure configurations was obtained from the experimental results. The extracted transition strengths were compared with those calculated with the state-of-the-art symmetry-conserving configuration-mixing (SCCM) and five-dimentional collective Hamiltonian (5DCH) approaches in order to shed light on the nature of the observed structures in the $^{188}$Hg nucleus. An oblate, a normal- and a super-deformed prolate bands were predicted and their underlying shell structure was also discussed.
Comment: v1: 13 pages, 10 figures, comparison between IBM-CM and SCCM calculations; v2: 16 pages, 13 figures, discussion on the mixing amplitudes from the experimental B(E2) values, comparison between SCCM and 5DCH calculations
Comment: v1: 13 pages, 10 figures, comparison between IBM-CM and SCCM calculations; v2: 16 pages, 13 figures, discussion on the mixing amplitudes from the experimental B(E2) values, comparison between SCCM and 5DCH calculations