First search for double β decay of dysprosium

A search for double β decay of dysprosium was realized for the first time with the help of an ultra-low background HP Ge γ detector. After 2512 h of data taking with a 322 g sample of dysprosium oxide limits on double beta processes in 156Dy and 158Dy have been established on the level of image. Possible resonant double electron captures in 156Dy and 158Dy were restricted on a similar level. As a by-product of the experiment we have measured the radioactive contamination of the Dy2O3 sample and set limits on the α decay of dysprosium isotopes to the excited levels of daughter nuclei as image.