  Liquid xenon-based direct detection dark matter experiments have recently
expanded their searches to include high-energy nuclear recoil events as
motivated by effective field theory dark matter and inelastic dark matter
interaction models, but few xenon recoil calibrations above 100 keV are
currently available. In this work, we measured the scintillation and ionization
yields of xenon recoils up to 426 keV. The experiment uses 14.1 MeV neutrons to
scatter off xenon in a compact liquid xenon time projection chamber and produce
quasi-monoenergetic xenon recoils between 39 keV and 426 keV. We report the
xenon recoil responses and their electric field-dependence for recoil energies
up to 306 keV; due to the low event statistics and the relatively mild field
dependence, the yield values at higher energies are reported as the average of
xenon responses for electric fields between 0.2-2.0 kV/cm. This result will
enable xenon-based dark matter experiments to significantly increase their high
energy dark matter sensitivities by including energy regions that were
previously inaccessible due to lack of calibrations.
