Cerenkov light identification with Si low-temperature detectors with sensitivity enhanced by the Neganov-Luke effect

A new generation of cryogenic light detectors exploiting the Neganov-Luke effect to enhance the thermal signal has been used to detect the Cherenkov light emitted by electrons interacting in TeO2 crystals. With this mechanism a high significance event-by-event discrimination between α and β/γ interactions at the Te130 neutrino-less double-β decay Q value of 2527.515±0.013 keV has been demonstrated. This measurement opens the possibility of drastically reducing the background in cryogenic experiments based on TeO2.