Neutralino WIMP dark matter annihilation

We systematically compute the annihilation rate for winos and higgsinos into the final state relevant for indirect Dark matter detection experiments, gamma + X. The radiative corrections to this process receive enhancement from the large Bloch-Nordsieck-Violating Sudakov logarithm, log(2 M_chi/M_W) and a non-perturbative long range gauge boson exchange (Sommerfeld enhancement). We resum the double logs and include single logs to fixed order using a formalism that combines nonrelativistic and soft-collinear effective field theories. For the wino case, we present exclusion plots in the TeV mass range, At the thermal relic mass of 3 TeV, LL' corrections result in a ~30% reduction in rate relative to tree level calculations. Nonetheless, single logs do not save the wino, and it is still excluded by an order of magnitude. Experimental cuts produce an endpoint region which, our results show, significantly effects the higgsino rate at its thermal-relic mass near 1 TeV and is deserving of further study.