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

Understand

The annihilation cross section of weakly interacting TeV scale dark matter particles $\chi^0$ 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 $\chi^0\chi^0\to \gamma+X$ in the vicinity of the maximal photon energy $E_\gamma = m_\chi$ with NLL' accuracy from the case of narrow photon energy resolution $E^\gamma_{\rm res}$ of order $m_W^2/m_\chi$ to intermediate resolution of order $E^\gamma_{\rm res} \sim m_W$.
• 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.