Nuclear structure of196Au:More evidence for its supersymmetric description

Abstract

Excited states in ${}^{196}\mathrm{Au},$ populated in the ${}^{196}\mathrm{Pt}(p,n)$ and $(d,2n)$ reactions, were investigated by in-beam $\ensuremath{\gamma}$-ray and conversion-electron spectroscopy. Two only weakly connected level structures, built on the ${2}^{\ensuremath{-}}$ ground state (negative-parity level scheme) and on the ${5}^{+}$ isomer at $84.7$ keV (positive-parity level scheme), are observed. The point of main effort of the present work was the investigation of the negative-parity level scheme in connection with its description within the framework of an extended supersymmetry. For this level scheme we observe 25 excited states up to an excitation energy of $500$ keV, of which 23 had already been identified in a recent study of ${}^{196}\mathrm{Au}$ by transfer reactions. From 500 to $800$ keV we observe 28 additional levels compared to 20 levels observed in the transfer reactions. The excitation energies derived in the studies of the $(p,n)$ compound reaction and the $(p,d)$ transfer reaction agree within 1 keV, and the complementary information obtained from the two reactions led to improved spin determinations. The negative-parity level structure is compared with the predictions of the extended supersymmetry.