New Yrast and Non-Yrast States in {sup 136}I and Medium Spin-Structure of {sup 136}I and {sup 136}Xe: Roles of the Proton {ital d}{sub 5/2} and the Neutron {ital h}{sub 9/2} Orbitals Beyond {sup 132}Sn
Authors
Lozeva, R.; Stefanova, E.; Naidja, H.; Nowacki, F.; Rzaca-Urban, T.; Wisniewski, J.; Urban, W.; Ahmad, I.; Blanc, A.; De France, G.; Greene, J. P.
Abstract
In this article we report on the observation of new yrast and non-yrast states in I-136, populated in the prompt-y spectroscopy EXILL campaign at the ILL using both U-235(n,f) and Pu-241(n,f) reactions. We propose an extension of the level scheme and interpretation of the new spectroscopic results in comparison to state-of-the-art shell-model calculations. We discuss the role of the proton d(5/2) orbital in the structure of this nucleus with Z = 53 and the energy split between the pi d(5/2) and pi g(7/2) orbitals. We also provide a complete overview of all experimental information about this nucleus and include new data from Cf-252, Cm-248 fission and beta decay of Te-136 to I-136. We give a new interpretation of I-136 and its decay to Xe-136 in terms of the influence of the neutron h(9/2) orbital and the Gamow-Teller strength for N = 83.