Search for a Non-Relativistic Component in the Spectrum of Cosmic Rays
  at Earth
  Dark matter particles gravitationally bound to our galaxy should exhibit a
characteristic speed distribution limited by their escape velocity at the
position of the Earth ($v_{esc}\simeq$ 550 km/s). An ongoing search for
anomalous cosmic rays at Earth, kinematically similar to cold dark matter, is
described. The technique can discriminate between these and known slow-moving
particles such as neutrons, would be sensitive to telltale signatures from
presently unexplored candidates, and offers the possibility of identifying the
mediating type of interaction (nuclear vs. electron recoils). Studies of
background identification and abatement in a shallow underground site are
presented. The expected reach of the method is discussed, and illustrated by
obtaining the first limits for dark matter particles lighter than 100
MeV/c$^{2}$ interacting via nuclear recoils.
