Probing Sub-GeV Mass Strongly Interacting Dark Matter with a Low-Threshold Surface Experiment

Using data from the $\nu$-cleus detector, based on the surface of Earth, we place constraints on dark matter in the form of strongly interacting massive particles (SIMPs) which interact with nucleons via nuclear-scale cross sections. For large SIMP-nucleon cross sections, the sensitivity of traditional direct dark matter searches using underground experiments is limited by the energy loss experienced by SIMPs, due to scattering with the rock overburden and experimental shielding on their way to the detector apparatus. Hence, a surface-based experiment is ideal for a SIMP search, despite the much larger background resulting from the lack of shielding. We show using data from a recent surface run of a low-threshold cryogenic detector that values of the SIMP-nucleon cross section up to approximately ${10}^{-27}{\mathrm{cm}}^2$ can be excluded for SIMPs with masses above 100 MeV.

Figure 1

Recoil spectra of 1 GeV mass SIMP dark matter for different values of the interaction cross section with nucleons ${\sigma }_n$, averaged over the duration of the experimental run time, for the 2017 surface run configuration. We also show as black points the data from the dark matter search performed by the CRESST Collaboration using the $\nu$-cleus experiment in Ref. [8], which we use to set exclusion limits in this work.

Figure 2

Excluded regions of DM mass and cross section at 95% confidence from various “direct” experiments (filled), including our reanalysis of the data from the dark matter search performed by the CRESST Collaboration with the $\nu$-cleus apparatus in Ref. [8], and the projected region of exclusion (dashed line) from a surface run using the apparatus described in this work with a low-energy threshold of 4 eV.