New nuclear structure data beyond ¹³⁶Sn

¹ CSNSM, CNRS/IN2P3, Université Paris-Saclay, 91405 Orsay Campus, France
² IPHC, CNRS/IN2P3, Université de Strasbourg, 67037 Strasbourg, Cedex 2, France

^* Corresponding author: radomira.lozeva@csnsm.in2p3.fr

Published online: 16 May 2018

Abstract

Exotic nuclei beyond the ¹³²Sn double shell-closure are influenced by both the Sn superfluity and the evolving collectivity only few nucleons away. Toward even more neutron-rich nuclei, especially at intermediate mass number, the interplay between single-particle and collective particle-hole excitations competes. In some cases with the extreme addition of neutrons also other effects as the formation of neutron skin, stabilization as sub-shell gaps or orbital crossings may be expected. The knowledge of nuclear ingredients is especially interesting beyond ¹³²Sn and little is known on how the excitation modes develop with the addition of both protons and neutrons and for example systematic prompt and decay studies can be such very sensitive probe. Recently, we have approached this region of nuclei in several experimental measurements following ²³⁸U projectile fission on ⁹Be and n-induced fission on ²⁴¹Pu and ²³⁵U. Consistent data analysis allows to access various spins and excitation energies and provide new input to theory. Examples from these studies on several nuclei in the A~140 region were presented during the conference together with the possible interpretation of the new data. Here, we will illustrate one example on ¹³⁶I using two complementary data sets.