The DAMA Project: Achievements And Perspectives In Rare Process Searches.pdf

Unveiling Rare Processes and Dark Matter Insights

The DAMA (Dark Matter in Atomic and Molecular Systems) collaboration, involving institutions like the University of Roma "Tor Vergata" and INFN, has made significant strides in rare process research and dark matter detection. Their achievements include:

Key Results:

First observations: Detecting α decays of 151Eu using a CaF2(Eu) scintillator and 190Pt to an excited state of 186Os.
Improved sensitivity: Significantly enhancing experimental sensitivities in the search for 2β decays, particularly for isotopes like 48Ca, 100Mo, 116Cd, and 150Nd.
Diverse searches: Exploring a range of rare processes including N, NN, and NNN decay into invisible channels in 129Xe and 136Xe; spontaneous transitions in 23Na and 127I; PEP violating processes; correlated e+e- pair emission in α decays of 241Am; cluster decays in 127I, 138La, and 139La; and solar axion searches.

Implications:

Dark Matter Exploration: DAMA's work highlights the challenge of detecting dark matter particles, which often interact only through gravity and are difficult to distinguish from background radiation. They investigate various dark matter candidates, including Inelastic Dark Matter and sterile neutrinos.
Model-Independent Signatures: The project emphasizes the importance of developing model-independent techniques for recognizing dark matter signals amidst complex backgrounds.
Statistical Subtractions: They address the issue of electromagnetic background contamination by employing sophisticated statistical methods to subtract these contributions, accounting for both systematic effects and lost candidates with pure electromagnetic production.

Direct Detection Approaches:

DAMA employs diverse direct detection techniques:

Ionization: Using materials like Ge and Si to measure ionization from dark matter interactions.
Scintillation: NaI(Tl), LXe, and CaF2(Eu) scintillators detect light produced by dark matter-nucleon interactions.
* Bolometers: TeO2, Ge, and CaWO4 materials measure heat deposits from dark matter particle interactions.

Perspectives:

The DAMA project continues to contribute significantly to our understanding of rare processes and the nature of dark matter. Future work will involve refining detection techniques, exploring new dark matter candidates, and deepening the collaboration's global reach.