Search for mixed-symmetry states in ²¹²Po

In this work we present an experiment dedicated to searching for quarupole- collective isovector valence-shell excitation — the states with so-called mixed proton-neutron symmetry (MSSs), in the nucleus ²¹²Po. The states of interest were populated and studied by an α-transfer reaction. The experiment provides indication for existence of one-phonon MSS in the nucleus ²¹²Po which is the first experimentally identified MSS in the region around double magic nucleus ²⁰⁸Pb.