Heavy Dark Matter Annihilation from Effective Field Theory
  We formulate an effective field theory description for SU(2)$_L$ triplet
fermionic dark matter by combining nonrelativistic dark matter with gauge
bosons in the soft-collinear effective theory. For a given dark matter mass,
the annihilation cross section to line photons is obtained with 5% precision by
simultaneously including Sommerfeld enhancement and the resummation of
electroweak Sudakov logarithms at next-to-next-to-leading logarithmic order.
Using these results, we present more accurate and precise predictions for the
gamma-ray line signal from annihilation, updating both existing constraints and
the reach of future experiments.
