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 E_γ = m_χ 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.