Abstract
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+1 → 2+1 ), Q(2+1 ), and g(2+1 ). The results indicate that the first-excited state, 2+1 , composed of the simple 2p ⊕ 2n system, is prolate deformed, and its wavefunction is dominated by neutron degrees of freedom, but not to the extent previously suggested. It is demonstrated that extreme sensitivity of g(2+1 ) to the proton and neutron contributions to the wavefunction provides unique insight into the nature of emerging collectivity, and g(2+1 ) was used to differentiate among several state-of-the-art theoretical calculations. Our results are best described by the most recent shell model calculations.
