$\beta$-delayed $\gamma$-ray spectroscopy of $^{196}$Hg and its description within the extended supersymmetry

The concept of nuclear structure SUSY has been observed and investigated in the Au-Pt mass region. It allows the simultaneous description of different nuclei forming so-called supermultiplets. All members of a supermultiplet are distinguished by a constant number of IBFM $\nu$- and $\pi$-bosons and -fermions. The most popular example is the `magic square' consisting of $^{194,195}$Pt and $^{195,196}$Au. Recently, efforts were made to investigate the expansion of the Au-Pt supermultiplets by a fifth member: the neighboring even-even Hg isotopes. For the square around $^{194}$Pt, this corresponds the 2-fermion--5-boson supermultiplet member $^{196}$Hg. We report on a $\gamma\gamma$ angular-correlation experiment to complete the data on low-spin states in $^{196}$Hg. It was performed at WSNL of Yale University using a 28-MeV proton beam activating an enriched $^{198}$HgS target. The $\gamma$-rays following the decay of the $\beta$-unstable $^{196}$Tl were observed off-beam with the YRAST-Ball Clover array. We present our results and discuss the description of $^{196}$Hg within the extended supersymmetry model.