Hunting for Heavy Winos

I will discuss recent progress in calculating a precision photon spectrum for heavy wino annihilation to photons, along with implications for indirect detection experiments.  I will review arguments that the 3 TeV mass wino is one of the simplest WIMP dark matter candidates.  Then I will discuss how the large separation of scales from 3 TeV to the weak scale leads to a breakdown of perturbation theory.  I will demonstrate how one can rely on modern effective field theory techniques to restore the convergence of the perturbative expansion, and will discuss our precision prediction for the wino annihilation spectrum.  I will review the status of searching for these photons using a ground based air Cherenkov telescope array (the H.E.S.S. experiment), along with the impact of our calculation on the interpretation of these limits.