CR electrons and positrons: what we have learned in the latest three years and future perspectives

TL;DR

This paper reviews recent discoveries of excess cosmic ray electrons and positrons, discusses a simple model explaining these observations, and explores uncertainties and future research directions in understanding their sources.

Contribution

It introduces a phenomenological model that coherently explains recent cosmic ray electron and positron data, highlighting key astrophysical uncertainties and future experimental prospects.

Findings

Confirmation of a new electron and positron spectral component by Fermi-LAT

A simple model can describe all current data sets coherently

Astrophysical uncertainties limit precise source characterization

Abstract

After the PAMELA finding of an increasing positron fraction above 10 GeV, the experimental evidence for the presence of a new electron and positron spectral component in the cosmic ray zoo has been recently confirmed by Fermi-LAT. We show that a simple phenomenological model which assumes the presence of a primary electron and positron extra component allows a consistent description of all available data sets. We then describe the most relevant astrophysical uncertainties which still prevent to determine the electron+positron source properties from those data and the perspectives of forthcoming experiments.