Evolution of proton single-particle states in neutron-rich Sb isotopes beyond $N=82$

Evolution of proton single-particle states in neutron-rich Sb isotopes beyond $N = 82$

A. Jungclaus et al.

Phys. Rev. C 102, 034324 – Published 23 September 2020

Abstract

The $β$ decay of the semimagic Sn isotopes ${}^{136, 137, 138}{Sn}$ has been studied at the Radioactive Isotope Beam Factory at the RIKEN Nishina Center. The first experimental information on excited states was obtained for ${}^{137}{Sb}$ while, in the case of ${}^{136}{Sb}$ , the established excitation scheme could be extended by ten previously unidentified levels. In the decay of the most-neutron-rich isotope ${}^{138}{Sn}$ , two $γ$ rays were observed for the first time. The new experimental results, in combination with state-of-the-art shell-model calculations, provide the first information with respect to the evolution of the $0 g_{7 / 2}$ and $1 d_{5 / 2}$ proton single-particle states with increasing neutron number beyond $N = 84$ .