Composite Dark Matter and Puzzles of Dark Matter Searches

TL;DR

This paper explores a novel dark matter candidate, O-helium atoms, which could explain DAMA experiment results through nuclear interactions, despite evading traditional detection methods.

Contribution

It proposes that O-helium atoms, formed by stable charged particles bound to helium, can account for DAMA signals via radiative capture, offering a new perspective on dark matter detection.

Findings

O-helium atoms can produce annual modulation signals in DAMA experiments.

Radiative capture of OHe by nuclei explains observed energy release.

OHe dark matter evades detection in cryogenic underground experiments.

Abstract

Positive results of dark matter searches in DAMA/NaI and DAMA/LIBRA experiments, being put together with the results of other groups, can imply nontrivial particle physics solutions for cosmological dark matter. Stable particles with charge -2, bound with primordial helium in O-helium "atoms" (OHe), represent a specific Warmer than Cold nuclear-interacting form of dark matter. Slowed down in the terrestrial matter, OHe is elusive for direct methods of underground Dark matter detection used in cryogenic experiments. However radiative capture of OHe by Na and I nuclei can lead to annual variations of energy release in the interval of energy 2-5 keV in DAMA/NaI and DAMA/LIBRA experiments.