Electroweak resummation of neutralino dark-matter annihilation into high-energy photons

We consider the resummation of large electroweak Sudakov logarithms for the annihilation of neutralino DM with (TeV) mass to high-energy photons in the minimal supersymmetric standard model, extending previous work on the minimal wino and Higgsino models. We find that NLL resummation reduces the yield of photons by about 20% for Higgsino-dominated DM at masses around 1 TeV, and up to 45% for neutralinos with larger wino admixture at heavier masses near 3 TeV. This sizable effect is relevant when observations or exclusion limits are translated into MSSM parameter-space constraints.