Owing to its low electronic noise and flexible target materials, the Spherical Proportional Counter (SPC) with a single electron detection threshold can be utilized to search for sub-GeV dark matter (DM). In this work, we investigate the prospects for light DM direct detection through the DM-nucleus Migdal effect in the DARKSPHERE detector. We consider the different DM velocity distributions and momentum-transfer effects. For Xenon and Neon targets, we find that the DM mass mDM can be probed down to as low as mDM∼O(10) MeV, and the derived bounds on the DM-nucleus scattering cross section σˉn are sensitive to the high-velocity tails of the DM velocity distribution, which can be altered by orders of magnitude for the different DM velocity distributions in the region mDM<10 MeV.
@article{arxiv.2309.09740,
title = {Probing Light DM through Migdal Effect with Spherical Proportional Counter},
author = {Yuchao Gu and Jie Tang and Lei Wu and Bin Zhu},
journal= {arXiv preprint arXiv:2309.09740},
year = {2023}
}