High-K isomers: A status report

High-K isomers provide one with a platform to investigate two different and interesting physics issues. One is the nature and validity of the K quantum number as a function of angular momentum, and the other is the intriguing interplay of single-particle and collective degrees of freedom in the nucleus. Recent measurements, with newer gamma-detector arrays and improved triggering for isomeric events, have revealed decays with hindrances that are unusually low by many orders of magnitude, and have led to reevaluation of the understanding of the mechanisms responsible for the violation of K-selection rules. Results from recent experiments in the A ∼ 180 region are discussed in the context of the emerging set of new data, and compared with calculations that attempt to distinguish between the mechanism of Coriolis mixing and γ-funneling that have been proposed as possible mechanisms for these unusual decays