Dark Matter interpretations of the e± excesses after FERMI

2009/05/31 by Patrick Meade, Michele Papucci, Alessandro Strumia +2 · 211 citations
Physics and Astronomy · #Annihilation #Astrophysics #Astrophysics and Cosmic Phenomena #Atomic physics #Compton scattering #Cosmic ray #Dark Matter and Cosmic Phenomena #Dark matter #Electron #Fermi Gamma-ray Space Telescope #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Photon #Physics #Positron #Quantum mechanics #hep-ph

paper · pdf · doi:10.1016/j.nuclphysb.2010.01.012

published in Nuclear Physics B 831(1-2), 178-203 (Elsevier BV) · 30 pages, 13 figures. Final and updated version

openalex publication_date 2010/01/19 · arxiv created 2010/02/24 · arxiv updated 2010/02/26 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

The cosmic-ray excess observed by PAMELA in the positron fraction and by FERMI and HESS in the electron + positron flux can be interpreted in terms of DM annihilations or decays into leptonic final states. Final states into tau's or 4mu give the best fit to the excess. However, in the annihilation scenario, they are incompatible with photon and neutrino constraints, unless DM has a quasi-constant density profile. Final states involving electrons are less constrained but poorly fit the excess, unless hidden sector radiation makes their energy spectrum smoother, allowing a fit to all the data with a combination of leptonic modes. In general, DM lighter than about a TeV cannot fit the excesses, so PAMELA should find a greater positron fraction at higher energies. The DM interpretation can be tested by FERMI gamma observations above 10 GeV: if the electronic excess is everywhere in the DM halo, inverse Compton scattering on ambient light produces a well-predicted gamma excess that FERMI should soon detect.

Citations

• Possible evidence for dark matter annihilations from the excess microwave emission around the center of the Galaxy seen by the Wilkinson Microwave Anisotropy Probe
• Study of TeV neutrinos with upward showering muons in Super-Kamiokande
• Astrophysical signatures of secluded dark matter
• Near-infrared flares from accreting gas around the supermassive black hole at the Galactic Centre
• A Cosmic-Ray Positron Anisotropy due to Two Middle-Aged, Nearby Pulsars?
• PAMELA data and leptonically decaying dark matter
• TeV Gamma Rays from Geminga and the Origin of the GeV Positron Excess
• Explosive Dark Matter Annihilation
• Bremsstrahlung, Synchrotron Radiation, and Compton Scattering of High-Energy Electrons Traversing Dilute Gases
• Nonperturbative effect on dark matter annihilation and gamma ray signature from the galactic center
• An anomalous positron abundance in cosmic rays with energies 1.5–100 GeV
• Effective theory of Dirac dark matter
• Energy Spectrum of Cosmic-Ray Electrons at TeV Energies
• A theory of dark matter
• Minimal Dark Matter predictions for galactic positrons, anti-protons, photons
• Dark matter through the axion portal
• CMB constraints on dark matter models with large annihilation cross section
• Hidden vector dark matter
• Positrons from dark matter annihilation in the galactic halo: Theoretical uncertainties