Matching resummed endpoint and continuum γ-ray spectra from dark-matter annihilation

Abstract

For the minimal wino and Higgsino benchmark models we provide accurate energy spectra of high-energy photons from TeV scale dark-matter annihilation χχ→γ+X by merging electroweak Sudakov resummation near maximal energy with the electroweak parton-shower PPPC4DM, and accounting for the Sommerfeld effect. Electroweak resummation significantly changes the shape of the photon-energy spectrum in the wide range Eγ∼(0.6…1)mχ and hence the form of the so-called “line-signal”.