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 of the stock Hf foil was studied in detail, in addition to an analysis of data collected over 310 days to search for rare processes that can occur in natural Hf isotopes. Firstly, limits on alpha decays of all natural Hf isotopes to the first excited state of the daughter nuclides were established in the range of 10¹⁶–10¹⁸a (90% C.L.). Secondly, a search for modes of double electron capture and electron capture with positron emission in ${}^{174}\text{Hf}$ was performed, yielding half-life limits 10¹⁶–10¹⁸a (90% C.L.). Lastly, novel dark matter-induced nuclear excitations in hafnium isotopes were investigated. For dark matter with 1 TeV/$c^2$ mass, leading limits on the inelastic dark matter–nucleon cross section are set for mass splittings in the range 428 keV $<{\delta }_M<$ 473 keV in the adopted model framework.

在Laboratori Nazionale del Gran Sasso实验室使用改良的超低本底高纯度检测器对样品进行检测，该检测器具有优化的样品到检测器几何形状。除了分析在310天内收集的数据以寻找天然Hf同位素中可能发生的稀有过程外，还对储备Hf箔的放射线纯度进行了详细研究。首先，将所有天然Hf同位素的α衰变限制在子核素的第一个激发态的范围确定为10 ¹⁶ –10 ¹⁸ a（90％CL）。其次，寻找双电子俘获和正电子发射电子俘获的模式。${}^{174}\text{高频}$进行了测试，得出半衰期极限为10 ¹⁶ –10 ¹⁸ a（90％CL）。最后，研究了dark同位素中暗物质诱发的新型核激发。对于1 TeV /的暗物质$C^{\mathrm{2个}}$ 质量，在428 keV范围内对质量分裂设置了非弹性暗物质-核子横截面的超前极限 $<{\delta }_{\mathrm{中号}}<$ 在采用的模型框架中为473 keV。