Positrons from dark matter annihilation in the galactic halo: uncertainties

TL;DR

This paper investigates the uncertainties in detecting positrons from dark matter annihilation in the galactic halo, emphasizing the impact of astrophysical factors on the expected signals and comparing predictions with experimental data.

Contribution

It provides novel solutions to positron propagation equations and quantifies astrophysical uncertainties affecting dark matter indirect detection signals.

Findings

Uncertainty in low-energy positron spectra is significant.

Propagation models influence the predicted positron flux.

Comparison with experimental data constrains dark matter models.

Abstract

Indirect detection signals from dark matter annihilation are studied in the positron channel. We discuss in detail the positron propagation inside the galactic medium: we present novel solutions of the diffusion and propagation equations and we focus on the determination of the astrophysical uncertainties which affect the positron dark matter signal. We show that, especially in the low energy tail of the positron spectra at Earth, the uncertainty is sizeable and we quantify the effect. Comparison of our predictions with current available and foreseen experimental data are derived.