New minimal, median, and maximal propagation models for dark matter searches with Galactic cosmic rays

TL;DR

This paper refines cosmic ray propagation models to better constrain dark matter signals, reducing uncertainties and providing detailed parameters for improved analysis of cosmic ray data.

Contribution

It updates the MIN-MED-MAX propagation models for cosmic rays, decreasing flux uncertainties and offering fitting formulas and detailed model parameters.

Findings

Uncertainty in fluxes reduced by a factor of 2 for positrons and 6 for antiprotons.

Provided fitting formulas for secondary fluxes of positrons and antiprotons.

Detailed model parameters and covariance matrices for refined analyses.

Abstract

Galactic charged cosmic rays (notably electrons, positrons, antiprotons and light antinuclei) are powerful probes of dark matter annihilation or decay, in particular for candidates heavier than a few MeV or tiny evaporating primordial black holes. Recent measurements by PAMELA, AMS-02, or VOYAGER on positrons and antiprotons already translate into constraints on several models over a large mass range. However, these constraints depend on Galactic transport models, in particular the diffusive halo size, subject to theoretical and statistical uncertainties. We update the so-called MIN-MED-MAX benchmark transport parameters that yield generic minimal, median and maximal dark-matter induced fluxes; this reduces the uncertainties on fluxes by a factor of about 2 for positrons and 6 for antiprotons, with respect to their former version. We also provide handy fitting formulae for the associated predicted secondary antiproton and positron background fluxes. Finally, for more refined analyses, we provide the full details of the model parameters and covariance matrices of uncertainties.