COSINUS - throwing light on a long-standing dark matter claim with low-temperature detectors

Florian Reindl
(HEPHY)

The nature of dark matter is one of the major open questions of present (particle) physics. Direct detection experiments aim to observe interactions of dark matter particles in earth-bound detectors. Currently, their results are under tension: The DAMA/LIBRA experiment measures an annual modulation of the event rate, just as expected for dark matter which is, however, incompatible with results from numerous other direct dark matter searches. COSINUS was brought to life to give new insight on this controversy by using, as DAMA/LIBRA, NaI as target material, thus excluding potential target-material dependencies in the comparison of results. COSINUS detectors are cryogenic calorimeters with phonon-light-readout - unique in the field of NaI-based dark matter searches. They provide particle identification on an event-by-event basis allowing to confirm or reject dark matter - nucleus interactions as the origin of the DAMA/LIBRA signal. This talk will cover recent results of the first COSINUS prototypes which, to our knowledge, are the first measurements of NaI crystals as cryogenic calorimeter. The discussions of perspectives includes methods achieving a model-independent comparison of an annual modulation signature (DAMA/LIBRA) to a total rate measurement (COSINUS).