The ASTAROTH Project: enhanced low-energy sensitivity to Dark Matter annual modulation

ASTAROTH is a novel R&D project which aims at improving the physics reach of future direct dark matter detection experiments based on NaI(Tl) scintillating crystals. There is a strong need to test the long standing DAMA positive observation of an annual modulation that could be due to Dark Matter (DM), with the same target material and in a model independent way. ASTAROTH aim is the enhancement of the sensitivity to the annual modulation signal, compared with present technology, by lowering the detection energy threshold in order to observe sub-keV recoils for the first time. This can be achieved by reading the scintillation light from the NaI(Tl) crystals with arrays of Silicon PhotoMultipliers (SiPM), and placing the detectors in a cryogenic environment. SiPMs feature lower dark noise than Photomultiplier Tubes (PMTs) at T < 150 K and allow for higher light collection. The cooling medium is liquid Argon, as it is an excellent scintillator that can be instrumented to act as a veto against several backgrounds. Here we present the status of the ASTAROTH project, introducing the innovative design of the detector chamber that will be used for the demonstration of the technology. Then, we will show the preliminary results of our first ever measurements performed on a single NaI(Tl) crystal read out by one SiPM array in a cryogenic set-up cooled with liquid nitrogen.