New yrast and non-yrast states in I 136 and medium-spin structure of I 136 and Xe 136 : Roles of the proton d 5 / 2 and the neutron h 9 / 2 orbitals beyond Sn 132

In this article we report on the observation of new yrast and non-yrast states in $^{136}\mathrm{I}$, populated in the prompt-$\ensuremath{\gamma}$ spectroscopy EXILL campaign at the ILL using both $^{235}\mathrm{U}$(n,f) and $^{241}\mathrm{Pu}$(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 $\ensuremath{\pi}{d}_{5/2}\phantom{\rule{0.28em}{0ex}}\text{and}\phantom{\rule{0.28em}{0ex}}\ensuremath{\pi}{g}_{7/2}$ orbitals. We also provide a complete overview of all experimental information about this nucleus and include new data from $^{252}\mathrm{Cf},^{248}\mathrm{Cm}$ fission and $\ensuremath{\beta}$ decay of $^{136}\mathrm{Te}$ to $^{136}\mathrm{I}$. We give a new interpretation of $^{136}\mathrm{I}$ and its decay to $^{136}\mathrm{Xe}$ in terms of the influence of the neutron ${h}_{9/2}$ orbital and the Gamow-Teller strength for $N=83$.