Beta-delayed neutron spectroscopy of ${}^{133}$In

Abstract

The decay properties of ${}^{133}$In were studied in detail at the ISOLDE Decay Station (IDS). The implementation of the Resonance Ionization Laser Ion Source (RILIS) allowed separate measurements of its $9/2^{+}$ ground state (${}^{133g}$In) and $1/2^{-}$ isomer (${}^{133m}$In). With the use of ${\hat{I}}^2$-delayed neutron and ${\hat{I}}^3$ spectroscopy, the decay strengths above the neutron separation energy were quantified in this neutron-rich nucleus for the first time. The allowed Gamow-Teller transition $9/2^{+}\to 7/2^{+}$ was located at 5.92 MeV in the ${}^{133g}$In decay with a logft = 4.7(1). In addition, several neutron-unbound states were populated at lower excitation energies by the First-Forbidden decays of ${}^{133g,m}$In. We assigned spins and parities to those neutron-unbound states based on the ${\hat{I}}^2$-decay selection rules, the logft values, and systematics.