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 $\mathcal{O}$(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 $20\mathrm{\%}$ for Higgsino-dominated DM at masses around 1~TeV, and up to $45\mathrm{\%}$ 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.