Positrons from dark matter annihilation in the galactic halo: theoretical uncertainties

TL;DR

This paper analyzes the uncertainties in predicting positron signals from dark matter annihilation in the galaxy, presenting new solutions for propagation models and assessing their implications for current and future experiments.

Contribution

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

Findings

Certain dark matter and propagation models fit existing positron data well

Predictions suggest upcoming experiments can distinguish signals from background

Propagation uncertainties significantly impact the interpretation of positron signals

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 find dark matter scenarios and propagation models that nicely fit existing data on the positron fraction. Finally, we present predictions both on the positron fraction and on the flux for already running or planned space experiments, concluding that they have the potential to discriminate a possible signal from the background and, in some cases, to distinguish among different astrophysical propagation models.