The DAMA experiment, for decades, claimed to detect modulated signals in a sodium iodide detector at a statistical significance of around 13σ by 2018, which might be attributed to dark matter. These claims were recently validated by other experiments using the same detectors, called COSINE-100 and ANAIS-112. The analysis of data from six years ago shows no modulation, ruling out the possibility of dark matter.
Independent NaI Searches
According to Phys.org, there have been two collaborations, namely COSINE-100 (Korea, US, UK) and ANAIS-112 (Spain), which have independently verified DAMA’s result using NaI crystals doped with thallium. Neither of them saw any modulation. ANAIS, with its data of three years, has failed to see any signal, in disagreement with DAMA at about the 3σ level, while COSINE-100, with its data of six and a half years, did not find any modulation either (which rejects DAMA at > 3σ level). The results have been published in refereed journals. Carlin et al. (2025) used the two data sets together and obtained a zero modulation amplitude fit.
Implications and outlook
These null results strengthen the view that DAMA’s modulation is not from WIMPs. Yale’s Reina Maruyama remarks that researchers can now “focus on finding a signal from dark matter rather than chase after a ghost”. The DAMA group continues to insist on a dark-matter interpretation, but experts caution that the modulation’s origin remains unclear. For example, CERN Courier notes that subtracting DAMA’s annual mean background can itself produce a sine-wave signature if the background drifts over time. Taken together, the COSINE and ANAIS findings make a dark-matter explanation very unlikely. The only way to settle the issue is further NaI tests (e.g., the SABRE experiment) and careful reanalysis of data.
