Hydrogenated carbon structures as directional sub-GeV dark matter detectors

We propose hydrogenated carbon structures as targets with a remarkable sensitivity to dark matter–nucleon interactions, in the mass range between 1 MeV and 100 MeV. The ejection of a proton following the interaction with a dark matter particle is a quasielastic process, with an extremely small energy threshold and a clear experimental signature. The proposed detectors are simple, technologically ready, and inexpensive. Yet, they can be considerably more sensitive than current experiments. They also allow strong directionality to be used toward efficient background rejection.