Detailed spectroscopy of doubly magic ${}^{132}$Sn

Abstract

The structure of the doubly magic ${}_{50}^{132}$Sn${}_{82}$ has been investigated at the ISOLDE facility at CERN, populated both by the $β^-$decay of ${}^{132}$In and $β^-$-delayed neutron emission of ${}^{133}$In. The level scheme of ${}^{132}$Sn is greatly expanded with the addition of 68 ${\hat{I}}^3$-transitions and 17 levels observed for the first time in the ${\hat{I}}^2$ decay. The information on the excited structure is completed by new ${\hat{I}}^3$-transitions and states populated in the ${\hat{I}}^2$-n decay of ${}^{133}$In. Improved delayed neutron emission probabilities are obtained both for ${}^{132}$In and ${}^{133}$In. Level lifetimes are measured via the Advanced Time-Delayed ${\hat{I}}^2{\hat{I}}^3{\hat{I}}^3$(t) fast-timing method. An interpretation of the level structure is given based on the experimental findings and the particle-hole configurations arising from core excitations both from the \textit{N} = 82 and \textit{Z} = 50 shells, leading to positive and negative parity particle-hole multiplets. The experimental information provides new data to challenge the theoretical description of ${}^{132}$Sn.

19 pages, 11 figures. Accepted for publication in Phys. Rev. C