Speaker
Description
CUPID-0 was a pilot experiment based on scintillating cryogenic calorimeters, originally designed to search for neutrinoless double beta decay of $^{82}$Se. The detector consisted of 26 radiopure ZnSe crystals operated as bolometers and coupled to bolometric light detectors. Over two years of continuous data taking, CUPID-0 demonstrated full $\alpha$ to $\beta/\gamma$ background discrimination, set the most stringent limit on the neutrinoless double beta decay of $^{82}$Se, and achieved the most precise measurement of the $^{82}$Se two-neutrino double beta decay half-life to date.
A key part of the CUPID-0 analysis effort was the construction of a detailed background model based on the reconstruction of all relevant radioactive contributions to the measured spectra. The resulting model not only supported the double-beta decay program, but also provided a well-controlled description of the residual background for next generation large-scale cryogenic calorimeter experiments. This is especially important for rare-event searches with continuous spectral signatures, where small spectral distortions can be hidden under low but non-negligible backgrounds.
In this contribution, we discuss the low-background performance of the CUPID-0 scintillating bolometer array and we present new applications of this technology in the search for new physics. In particular, we present novel analyses searching for feebly interacting particles through spectral distortions induced by sterile-neutrino emission in double beta decay, and through signals from solar axions. We report the first search for light dark matter candidates performed with the CUPID-0 technology, highlighting the potential of cryogenic calorimeters in the hunt for dark matter and other physics beyond the Standard Model.