Dark Matter Search in Nucleon, Pion, and Electron Channels from a Proton Beam Dump with MiniBooNE

A search for sub-GeV dark matterproduced from collisions of the Fermilab 8 GeV Booster protons with a steel beam dumpwas performed by the MiniBooNE-DM collaboration using data from $1.86 \times 10^{20}$ protons on target in a dedicated run. The MiniBooNEdetector, consisting of 818 tonnes of mineral oiland located 490 meters downstream of the beam dump, is sensitive to a variety of dark matterinitiated scattering reactions. Three dark matterinteractions are considered for this analysis: elastic scatteringoff nucleons, inelastic neutral pion production, and elastic scatteringoff electrons. Multiple data sets were used to constrain flux and systematic errors, and time-of-flight information was employed to increase sensitivity to higher dark mattermasses. No excess from the background predictions was observed, and 90$\%$ confidence level limits were set on the vector portal and leptophobic dark mattermodels. New parameter space is excluded in the vector portal dark mattermodel with a dark mattermass between 5 and 50 MeV c$^{-2}$.