Speaker
Description
The direct detection of particle dark matter through nuclear recoils at the keV scale remains a primary objective of underground experiments worldwide. NaI(Tl) scintillators are of particular interest due to their long-standing role in the search for an annual modulation signal, as reported by the DAMA/LIBRA experiment at the Gran Sasso National Laboratory, which still lacks an independent confirmation. Achieving lower energy thresholds and improved light collection is crucial to fully probe the relevant parameter space.
The ASTAROTH project, developed in Milan, aims to advance this field by operating NaI(Tl) crystals in a cryogenic environment and implementing, for the first time, a light readout based on large-area silicon photomultiplier (SiPM) arrays. This innovative approach is designed to overcome limitations and radioactivity of current-generation detectors, with the goal of lowering the energy threshold and extending sensitivity to sub-keV nuclear recoils, where a sizable fraction of the expected dark matter signal may reside.
In 2025, the first successful cryogenic data-taking campaigns were carried out at the LASA laboratory, coupling different SiPM matrices to a NaI(Tl) crystal inside a dedicated cryostat. In this contribution, we present the detector performance achieved so far and a few key developments ongoings to bring the experiment into the low background domain.