DAMA/LIBRA annual modulation and NaI tests
An experiment in Italy called DAMA/LIBRA has seen its event rate rise and fall once a year for over two decades, as expected if Earth moves through a cloud of dark matter while orbiting the Sun. Other experiments with the same crystal material, sodium iodide, see no such yearly change, so the cause of the DAMA signal is unknown.
Why it matters
Either a dark matter signal is hidden in a way no current model explains, or a result claimed at more than $13\,\sigma$ is an instrumental or analysis effect, and both outcomes change how direct detection claims are judged.
Review
N. Carlin et al. (COSINE-100 and ANAIS-112 Collaborations), Combined Annual Modulation Dark Matter Search with COSINE-100 and ANAIS-112, Phys. Rev. Lett. 135, 121002, 2025. https://doi.org/10.1103/9j7w-qp1c reference checked
Proof
- Signed record
- bae30d7e0bff…
- Public log
- Entry 239, in checkpoint 2,123
- Bitcoin date
- Block 969,698, 2026-10-03