UC Irvine

The LHC may produce light, weakly interacting particles that decay to dark matter, creating an intense and highly collimated beam of dark matter particles in the far-forward direction. We investigate the prospects for detecting this dark matter in two far-forward detectors proposed for a future forward physics facility: FASERν2, a 10-ton emulsion detector, and FLArE, a 10- to 100-ton LArTPC. We focus here on nuclear scattering, including elastic scattering, resonant pion production, and deep inelastic scattering, and devise cuts that efficiently remove the neutrino-induced background. In the invisibly decaying dark photon scenario, DM-nuclear scattering probes new parameter space for dark matter masses 5 MeV mχ 500 MeV. When combined with the DM-electron scattering studied previously, FASERν2 and FLArE will be able to discover dark matter in a large swath of the cosmologically favored parameter space with MeV mχ GeV.