Studies of multi-quasiparticle K-isomers in rare-earth and trans-fermium nuclei

Nuclear K-isomers play an important role in understanding the structure of deformed axially symmetric nuclei. Examples are presented of recent studies in the rare-earth region (A∼180) using deep-inelastic and multi- nucleon transfer reactions, and in the trans-fermium region (A∼250) using fusion-evaporation reactions. A specific two-level mixing scenario is invoked to explain the unusual decay of the K π = 13 + isomer in 174 Lu. The identification of 2- and 4-quasiparticle isomers in 254 No is discussed and predictions of similar isomers in neighboring No and Rf nuclei are presented.