A search for rare and induced nuclear decays in hafnium

A measurement of hafnium foil using a modified ultra-low-background high purity detector with optimized sample-to-detector geometry was performed at Laboratori Nazionale del Gran Sasso. Radiopurity the stock Hf studied in detail, addition to an analysis data collected over 310 days search for rare processes that can occur natural isotopes. Firstly, limits on alpha decays all isotopes first excited state daughter nuclides were established range 1016–1018a (90% C.L.). Secondly, modes double electron capture and positron emission Hf174 performed, yielding half-life Lastly, novel dark matter-induced nuclear excitations investigated. For matter 1 TeV/c2 mass, leading inelastic matter–nucleon cross section are set mass splittings 428 keV <?M< 473 adopted model framework.