Determine the origin of the DAMA/LIBRA annual-modulation signal

Determine whether the annual modulation observed by DAMA/LIBRA in NaI(Tl) detectors is caused by dark matter or by an unaccounted-for time-dependent background, thereby resolving the discrepancy with the null or incompatible results reported by other NaI(Tl)-based experiments.

Background

The DAMA/LIBRA experiment has reported a persistent annual modulation in NaI(Tl) detectors, interpreting it as potentially consistent with the expected modulation from Earth’s motion through the Galactic dark-matter halo. Independent experiments using the same target material, including ANAIS and COSINE, have reported no evidence supporting a compatible modulation and have found significant tension with the DAMA/LIBRA result.

The unresolved issue is whether the discrepancy arises from a genuine dark-matter signal in DAMA/LIBRA or from detector-specific, environmental, calibration-related, or other time-dependent backgrounds. The paper identifies continued measurements by SABRE, PICOLON, and other next-generation NaI(Tl) experiments as the direct route toward resolving this question through improved radiopurity, stability, and background control.

References

A particularly important unresolved issue is the DAMA/LIBRA annual-modulation signal, which has motivated extensive experimental and theoretical efforts for more than two decades. The central question is whether the observed modulation is caused by DM or by an unaccounted-for time-dependent background.

— State of the Art in Direct Dark Matter Detectors: Technologies, Performance, and Future Directions  (2610.01266 - Ghaith et al., 1 Oct 2026) in Section 7, Conclusions