Absolute electron and positron fluxes from PAMELA/Fermi and Dark Matter

TL;DR

This paper combines PAMELA and Fermi data to derive absolute electron and positron fluxes, revealing a positron excess at high energies that could suggest dark matter interactions.

Contribution

It provides the first combined analysis of absolute electron and positron fluxes from PAMELA and Fermi data, highlighting a potential positron excess at energies above 50 GeV.

Findings

Positron flux shows an excess at energies above 50 GeV.

Electron and positron fluxes follow power-law distributions.

Results support the possibility of dark matter contributing to positron excess.

Abstract

We extract the positron and electron fluxes in the energy range 10 - 100 GeV by combining the recent data from PAMELA and Fermi LAT. The {\it absolute positron and electron} fluxes thus obtained are found to obey the power laws: $E^{-2.65}$ and $E^{-3.06}$ respectively, which can be confirmed by the upcoming data from PAMELA. The positron flux appears to indicate an excess at energies $E\gsim 50$ GeV even if the uncertainty in the secondary positron flux is added to the Galactic positron background. This leaves enough motivation for considering new physics, such as annihilation or decay of dark matter, as the origin of positron excess in the cosmic rays.