Electromagnetic Moments of Radioactive 136Te and the Emergence of Collectivity 2p ⊕ 2n outside of Double-Magic 132Sn

• Published in: Physical review letters 2017-03, Vol.118 (9)
• Main Authors: Allmond, James M., Stuchberry, A. E., Baktash, Cyrus, Gargano, A., Galindo-Uribarri, Alfredo, Univ. of Tennessee, Knoxville, TN, Radford, David C., Bingham, C. R., Brown, B. Alex, Michigan State Univ., East Lansing, MI, Coraggio, L., Covello, A., Danchev, M., St. Kliment Ohridski Univ. of Sofia, Gross, Carl J., Hausladen, Paul, Itaco, N., Univ. of Campania, Caserta, Lagergren, Karin B., Padilla-Rodal, Elizabeth, Pavan, John R., Riley, Mark A., Stone, N. J., Univ. of Oxford, Stracener, Daniel W., Varner, Jr., Robert L., Yu, Chang-Hong
• Format: Article
• Language: English
• Subjects: NUCLEAR PHYSICS AND RADIATION PHYSICS
• ISSN: 0031-9007; 1079-7114

Radioactive 136Te has two valence protons and two valence neutrons outside of the 132Sn double shell closure, providing a simple laboratory for exploring the emergence of collectivity and nucleon- nucleon interactions. Coulomb excitation of 136Te on a titanium target was utilized to determine an extensive set of electromagnetic moments for the three lowest-lying states, including B(E2;0$+\atop{1}$→ 2$+\atop{1}$ ), Q(2$+\atop{1}$ ), and g(2$+\atop{1}$ ). The results indicate that the first-excited state, 2$+\atop{1}$ , composed of the simple 2p ⊕ 2n system, is prolate deformed, and its wave function is dominated by neutron degrees of freedom, but not to the extent previously suggested. It is demonstrated that extreme sensitivity of g(2$+\atop{1}$) to the proton and neutron contributions to the wave function provides unique insight into the nature of emerging collectivity, and g(2$+\atop{1}$ ) was used to differentiate among several state-of-the-art theoretical calculations. Finally, our results are best described by the most recent shell model calculations.