Electroweak lights from Dark Matter annihilations

TL;DR

This paper examines how electroweak gauge boson radiation affects the energy spectra of particles from Dark Matter annihilations, especially in cases where it can lift p-wave suppression and enhance indirect detection signals.

Contribution

It demonstrates that electroweak radiation can significantly modify annihilation spectra, introducing s-wave contributions in scenarios previously suppressed.

Findings

Electroweak radiation can lift p-wave suppression in Dark Matter annihilations.

Enhanced fluxes of stable particles from Dark Matter annihilations due to electroweak effects.

Implications for Dark Matter indirect detection experiments.

Abstract

The energy spectra of Standard Model particles originated from Dark Matter annihilations can be significantly altered by the inclusion of electroweak gauge boson radiation from the final state. A situation where this effect is particularly important is when a Majorana Dark Matter particle annihilates into two light fermions. This process is in p-wave and hence suppressed by the small value of the relative velocity of the annihilating particles. The inclusion of electroweak radiation eludes this suppression and opens up a potentially sizeable s-wave contribution to the annihilation cross section. I will discuss the impact of this effect on the fluxes of stable particles resulting from the Dark Matter annihilations, which are relevant for Dark Matter indirect searches.