Researchers have explored the interaction of dark matter (DM) with nucleons and nuclei within the framework of Composite Higgs Models (CHMs). In these models, the lightest Dirac composite particle (LDCP) can be stable and constitute a significant fraction of the observed relic dark matter abundance. The study focuses on the elastic scattering of the LDCP on nucleons, as well as on xenon (Xe) and argon (Ar) nuclei, considering a non-zero magnetic dipole moment for the LDCP.

The peculiarity of this scenario is that the LDCP's magnetic moment, its mass, and its coupling to the Higgs doublet are suppressed by an approximate U(1) symmetry. A non-zero magnetic dipole moment for the LDCP can lead to a substantial enhancement in the differential event rate in direct detection (DD) experiments, especially at low nuclear recoil energies. This effect could be key to its detection.

Assuming the LDCP constitutes at least 10% (ξ ≥ 0.1) of the relic dark matter, the authors have identified a region of the parameter space where this enhancement in the event rate could be potentially observable. Furthermore, they have specified some observables that could be useful in discriminating between dark matter fermions with a magnetic moment and other types of dark matter particles that do not possess similar electromagnetic properties. This opens a path to identify the nature of dark matter if a signal with these characteristics is detected.