DAMA/LIBRA: Rare Process Discoveries And Dark Matter Searches.pdf

Unveiling Rare Processes and Dark Matter Clues

The DAMA (Double Beta Decay Array) collaboration, encompassing institutions like INFN Roma Tor Vergata, LNGS, IHEP/Beijing, and several international partners, has made significant strides in the search for rare nuclear processes and dark matter particles. Their work is presented at the XI International Conference on New Frontiers in Physics (ICNFP 2022) in Crete.

Key Achievements:

First Observations: DAMA reported the first observation of:
Decays of 151Eu using a CaF2(Eu) scintillator.
Decays of 190Pt to the first excited level of 186Os and 174Hf using CHC crystals.
Improved Results in Rare Beta Decays: They significantly advanced knowledge on rare beta decays of several isotopes, including 113Cd, 113mCd, 48Ca, and more.
Search for Invisible Decays: DAMA conducted searches for neutral and neutrally-charged particle decays into invisible channels in 129Xe and 136Xe.
2β Decay Studies: The collaboration achieved best experimental sensitivities in the field for 2β decays with positron emission (in 106Cd). They also observed the first 2ν2β decay in 100Mo, 116Cd, and 150Nd.
Other Notable Studies: DAMA explored spontaneous transition of 23Na and 127I nuclei, PEP violation in sodium and iodine, correlated e+e- pair emission in 241Am decay, cluster decays in 127I, 138La, and 139La, CNC processes, and solar axion searches.

Dark Matter Investigation:

DAMA is also actively involved in dark matter (DM) research:

Search for Super-Heavy Elements: They conducted searches for long-lived super-heavy eka-tungsten isotopes using ZnWO4 and CdWO4 detectors.
Model-Independent Approach: DAMA emphasizes a model-independent approach to distinguish DM signals from backgrounds, opening avenues for identifying various DM candidates.
Limitations of Accelerators: While accelerators are crucial for exploring potential DM candidates, they cannot definitively identify the single dark matter particle or prove its existence. Multi-component non-baryonic DM remains a possibility.

Direct Detection Experiments:

DAMA classifies direct detection experiments based on their underlying technology:

Ionization Detectors: Using materials like Ge and Si.
Scintillation Detectors: Employing scintillators like NaI(Tl), LXe, and CaF2(Eu).
* Bolometers: Utilizing materials such as TeO2, Ge, and CaWO4.