K-selection or barrier penetration?

Questions on the validity of the K-selection rule for the decay of high spin isomers in deformed nuclei has been raised and an alternative mode by barrier penetration has been proposed. The present paper reports on a sensitive study of a K=14 isomer in 174Hf where 20 different branches decay from the same level and consistently show low hindrance factors. It is found that the hindrance factors depend on K but have smaller absolute values than expected. The question of a barrier penetration decay mode is still open. (orig.)