Hunt for sub-GeV dark matter at neutrino facilities: A survey of past and present experiments

We survey the sensitivity of past and present neutrino experiments to MeV-GeV scale vector portal dark matter and find that these experiments possess novel sensitivity that has not yet fully explored. Taking alpha(D) = 0.1 and a dark photon to dark matter mass ratio of three, the combined recast of previous analyses of Big European Bubble Chamber and a projection of NO nu A's sensitivity are found to rule out the scalar thermal target for dark matter masses between 10 and 100 MeV with existing data, while CHARM-11 and MINER nu A place somewhat weaker limits. These limits can be improved by off-axis searches using the NuMI beam line and the MicroBooNE, MiniBooNE, or ICARUS detectors and can even begin to probe the Majorana thermal target. We conclude that past and present neutrino facilities can search for light dark matter concurrently with their neutrino program and reach a competitive sensitivity to proposed future experiments.