Matrix element analyses of dark matter scattering and annihilation
  We provide a compendium of results at the level of matrix elements for a
systematic study of dark matter scattering and annihilation. We identify
interactions that yield spin-dependent and spin-independent scattering and
specify whether the interactions are velocity- and/or momentum-suppressed. We
identify the interactions that lead to s-wave or p-wave annihilation, and those
that are chirality-suppressed. We also list the interaction structures that can
interfere in scattering and annihilation processes. Using these results, we
point out situations in which deviations from the standard lore are obtained.
