학술논문
Effects of one valence proton on seniority and angular momentum of neutrons in neutron-rich $^{122-131}$Sb$_{51}$ isotopes
Document Type
Working Paper
Author
Biswas, S.; Lemasson, A.; Rejmund, M.; Navin, A.; Kim, Y. H.; Michelagnoli, C.; Stefan, I.; Banik, R.; Bednarczyk, P.; Bhattacharya, S.; Bhattacharyya, S.; Clément, E.; Crawford, H. L.; de France, G.; Fallon, P.; Frémont, G.; Goupil, J.; Jacquot, B.; Li, H. J.; Ljungvall, J.; Maj, A.; Ménager, L.; Morel, V.; Palit, R.; Pérez-Vidal, R. M.; Ropert, J.; Barrientos, D.; Benzoni, G.; Birkenbach, B.; Boston, A. J.; Boston, H. C.; Cederwall, B.; Collado, J.; Cullen, D. M.; Désesquelles, P.; Domingo-Pardo, C.; Dudouet, J.; Eberth, J.; Gonzalez, V.; Harkness-Brennan, L. J.; Hess, H.; Jungclaus, A.; Korten, W.; Labiche, M.; Lefevre, A.; Menegazzo, R.; Mengoni, D.; Million, B.; Napoli, D. R.; Pullia, A.; Quintana, B.; Ralet, D.; Recchia, F.; Reiter, P.; Saillant, F.; Salsac, M. D.; Sanchis, E.; Stezowski, O.; Theisen, Ch.; Valiente-Dobon, J. J.; Zielinska, M.
Source
Physical Review C 99, 064302 (2018)
Subject
Language
Abstract
The neutron-rich $^{122-131}$Sb isotopes were produced as fission fragments in the reaction $^{9}$Be($^{238}$U,~f) with 6.2 MeV/u beam energy. An unique setup, consisting of AGATA, VAMOS++ and EXOGAM detectors, was used which enabled the prompt-delayed gamma-ray ($\gamma$) spectroscopy of fission fragments in the time range of 100 ns - 200 $\mu$s. New isomers, prompt and delayed transitions were established in the even-A $^{122-130}$Sb isotopes. In the odd-A $^{123-131}$Sb isotopes, new prompt and delayed $\gamma$-ray transitions were identified, in addition to the confirmation of the previously known isomers. The half-lives of the isomeric states and the $B(E2)$ transition probabilities of the observed transitions depopulating these isomers were extracted. The experimental data was compared with the theoretical results obtained in the framework of Large-Scale Shell-Model (LSSM) calculations in a restricted model space. Modifications of several components of the shell model interaction were introduced to obtain a consistent agreement with the excitation energies and the $B(E2)$ transition probabilities in neutron-rich Sn and Sb isotopes. The isomeric configurations in Sn and Sb were found to be relatively pure. Further, the calculations revealed that the presence of a single valence proton, mainly in the $g_{7/2}$ orbital in Sb isotopes, leads to significant mixing (due to the $\nu\pi$ interaction) of: (i) the neutron seniorities ($\upsilon_{\nu}$) and (ii) the neutron angular momentum ($I_{\nu}$). The above features have a weak impact on the excitation energies, but have an important impact on the $B(E2)$ transition probabilities. In addition, a constancy of the relative excitation energies irrespective of neutron seniority and neutron number in Sn and Sb was observed.
Comment: 23 pages, 18 figures, 10 tables
Comment: 23 pages, 18 figures, 10 tables