Nuclear structure of Au-196: More evidence for its supersymmetric description

Excited states in (196)AU, populated in the Pt-196(p,n) and (d,2n) reactions, were investigated by in-beam gamma -ray and conversion-electron spectroscopy. Two only weakly connected level structures, built on the 2(-) 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)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.