Speaker
Description
The signal measured by the DAMA/LIBRA experiment matches the expectations of an annually modulating signal caused by particle dark matter (DM) from the galactic halo with very high statistical significance. At the same time, this result is in strong tension with null results from many other DM direct detection experiments. These tensions, however, critically depend on assumptions about the exact nature of DM, its interaction mechanism with the Standard Model, and other systematic uncertainties. An unambiguous, model- and detector-material-independent cross-check is therefore crucial, yet still pending.
The COSINUS experiment, located at the LNGS (Laboratori Nazionali del Gran Sasso) in Italy, will answer whether the signal recorded by the DAMA/LIBRA collaboration can originate from DM nuclear recoils. To achieve this, COSINUS employs ultrapure NaI crystals operated as cryogenic scintillating calorimeters, which renders it unique among NaI-based experiments (like DAMA/LIBRA) and allows a cross-check that is both DM-model- and quenching-factor-independent. This key technology is a combination of 1) using transition edge sensors (TESs) on NaI crystals at millikelvin temperatures to measure phonon signals caused by particle interactions, and 2) additionally capturing the scintillation light. The resulting advantages include a low threshold for nuclear recoils, absolute energy calibration using the phonon channel, superior energy resolution, and effective discrimination of electromagnetic backgrounds on an event-by-event basis due to the dual-channel readout.
This talk will discuss the latest results from the COSINUS prototype detectors, the status of the novel cryogenic low-background facility located at the LNGS, and the last steps of the commissioning towards starting the first physics data-taking campaign in late 2025.