Direct Detection of sub-GeV Dark Matter with Electrons from Nuclear Scattering [CL]

http://arxiv.org/abs/1711.09906


Dark matter (DM) particles with mass in the MeV to GeV range are an attractive alternative to heavier weakly-interacting massive particles. Direct detection of such light particles is challenging because the energy transfer in DM-nucleus interactions is small. If the recoiling atom is ionised, however, the resulting electron may be detected even if the nuclear recoil is unobservable. Considering the case of dual-phase xenon detectors, we demonstrate that including electron emission from nuclear recoils significantly enhances their sensitivity to sub-GeV DM particles. Existing experiments like LUX set world-leading limits on the DM-nucleon scattering cross section, and future experiments like LZ may probe the cross section relevant for thermal freeze-out. The proposed strategy is complementary to experiments looking for DM-electron scattering in scenarios where the DM particles couple with similar strength to protons and electrons.

Read this paper on arXiv…

M. Dolan, F. Kahlhoefer and C. McCabe
Wed, 29 Nov 17
40/69

Comments: 6 pages, 2 figures