COSINE-100 full dataset challenges the annual modulation signal of DAMA/LIBRA

Area of Science:

• Particle Physics
• Astrophysics
• Cosmology

Background:

• The DAMA/LIBRA collaboration has reported a persistent annual modulation signal for over 25 years, interpreted as evidence for dark matter interactions.
• However, this signal has not been independently confirmed by other experiments using different target materials, creating a significant puzzle in dark matter research.

Purpose of the Study:

• To conduct a model-independent test of the DAMA/LIBRA annual modulation claim.
• To investigate potential dark matter interactions using the same target material (sodium iodide) as DAMA/LIBRA.

Main Methods:

• The COSINE-100 collaboration analyzed 6.4 years of data from sodium iodide crystal detectors.
• Improved energy calibration and sophisticated time-dependent background modeling were employed.
• The analysis focused on detecting an annual modulation signal in a model-independent manner.

Main Results:

• No statistically significant evidence for an annual modulation signal was found.
• The results challenge the DAMA/LIBRA findings with a confidence level greater than 3 sigma.
• This indicates that the modulation observed by DAMA/LIBRA is unlikely to be caused by dark matter interactions.

Conclusions:

• The COSINE-100 experiment's findings cast doubt on the DAMA/LIBRA dark matter detection claim.
• This study represents a significant advancement in resolving the long-standing debate surrounding annual modulation signals in dark matter searches.
• Further investigation with different experimental approaches may be necessary to fully understand the observed phenomena.