Resummed photon spectrum from dark matter annihilation for intermediate and narrow energy resolution

The annihilation cross section of weakly interacting TeV scale dark matter particles χ0 into photons is affected by large quantum corrections due to electroweak Sudakov logarithms and the Sommerfeld effect. We extend our previous work on the resummation of the semi-inclusive photon energy spectrum in χ0χ0 → γ + X in the vicinity of the maximal photon energy Eγ = mχ with NLL’ accuracy from the case of narrow photon energy resolution Eresγ of order mW2/mχ to intermediate resolution of order Eresγ∼mW. We also provide details on the previous narrow resolution calculation. The two calculations, performed in different effective field theory set-ups for the wino dark matter model, are then shown to match well, providing an accurate representation up to energy resolutions of about 300 GeV