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. 
Grigory Ovanesyan, Tracy R. Slatyer, Iain W. Stewart
hep-ph astro-ph.CO astro-ph.HE nucl-th