The Cosmic Ray Lepton Puzzle

TL;DR

This paper reviews recent cosmic ray electron and positron measurements revealing excesses, discussing potential astrophysical and dark matter sources, and evaluates various theoretical explanations based on recent experimental data.

Contribution

It provides a comprehensive review of recent experimental results and critically assesses the strengths and weaknesses of existing theoretical models for cosmic ray lepton excesses.

Findings

Recent measurements show excesses in cosmic ray electrons and positrons.

Various sources like pulsars, supernova remnants, and dark matter are considered as explanations.

The paper discusses the pros and cons of different theoretical interpretations.

Abstract

Recent measurements of cosmic ray electrons and positrons by PAMELA, ATIC, Fermi and HESS have revealed interesting excesses and features in the GeV-TeV range. Many possible explanations have been suggested, invoking one or more nearby primary sources such as pulsars and supernova remnants, or dark matter. Based on the output of the TANGO in PARIS --Testing Astroparticle with the New GeV/TeV Observations in Positrons And electRons : Identifying the Sources-- workshop held in Paris in May 2009, we review here the latest experimental results and we discuss some virtues and drawbacks of the many theoretical interpretations proposed so far.