Generic dark matter signature for gamma-ray telescopes

Abstract

We describe a characteristic signature of dark matter (DM) annihilation or decay into gamma-rays. We show that if the total angular momentum of the initial DM particle(s) vanishes, and helicity suppression operates to prevent annihilation/decay into light fermion pairs, then the amplitude for the dominant 3-body final state f^+f^-γhas a unique form dictated by gauge invariance. This amplitude and the corresponding energy spectra hold for annihilation of DM Majorana fermions or self-conjugate scalars, and for decay of DM scalars, thus encompassing a variety of possibilities. Within this scenario, we analyze Fermi LAT, PAMELA and HESS data, and predict a hint in future Fermi gamma-ray data that portends a striking signal at atmospheric Cherenkov telescopes (ACTs).

9 pages, 4 figures. Version to appear in PRD

References in corpus (27)

• Observation of an anomalous positron abundance in the cosmic radiation
• Verifiable Radiative Seesaw Mechanism of Neutrino Mass and Dark Matter
• Bounds on Universal Extra Dimensions
• Measurement of the Cosmic Ray e+ plus e- spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope
• The Diversity and Similarity of Simulated Cold Dark Matter Halos
• Is the Lightest Kaluza-Klein Particle a Viable Dark Matter Candidate?
• TeV Symmetry and the Little Hierarchy Problem
• A new measurement of the antiproton-to-proton flux ratio up to 100 GeV in the cosmic radiation
• Probing the ATIC peak in the cosmic-ray electron spectrum with H.E.S.S
• A new determination of the extragalactic diffuse gamma-ray background from EGRET data
• Dark-matter sterile neutrinos in models with a gauge singlet in the Higgs sector
• New Gamma-Ray Contributions to Supersymmetric Dark Matter Annihilation
• Gamma Rays from Kaluza-Klein Dark Matter
• Little Higgs Dark Matter
• Time-Dependent Models for Dark Matter at the Galactic Center
• Gamma-ray continuum emission from the inner Galactic region as observed with INTEGRAL/SPI
• Full calculation of clumpiness boost factors for antimatter cosmic rays in the light of Lambda-CDM N-body simulation results
• Chiral Compactification on a Square
• High-energy electron observations by PPB-BETS flight in Antarctica
• Dark matter and pulsar signals for Fermi LAT, PAMELA, ATIC, HESS and WMAP data
• The WIMP Forest: Indirect Detection of a Chiral Square
• The WIMP of a Minimal Technicolor Theory
• A Unified Dark Matter Model in sUED
• Sterile neutrino dark matter in warped extra dimensions
• Fermi LAT Measurements of the Diffuse Gamma-Ray Emission at Intermediate Galactic Latitudes
• The New Extended Left-Right Symmetric Grand Unified Model with SO(3) Family Symmetry
• Shadow Fermions, Messenger Scalars and Leptogenesis

Cited by in corpus (40)

• Fermi LAT Search for Internal Bremsstrahlung Signatures from Dark Matter Annihilation
• GeV-Scale Thermal WIMPs: Not Even Slightly Dead
• On the Importance of Electroweak Corrections for Majorana Dark Matter Indirect Detection
• Loopy Constraints on Leptophilic Dark Matter and Internal Bremsstrahlung
• W/Z Bremsstrahlung as the Dominant Annihilation Channel for Dark Matter, Revisited
• On the role of electroweak bremsstrahlung for indirect dark matter signatures
• W/Z Bremsstrahlung as the Dominant Annihilation Channel for Dark Matter
• Antiproton constraints on dark matter annihilations from internal electroweak bremsstrahlung
• Dark matter annihilations into two light fermions and one gauge boson: general analysis and antiproton constraints
• Radio and gamma-ray constraints on dark matter annihilation in the Galactic center
• A clear Dark Matter gamma ray line generated by the Green-Schwarz mechanism
• Dark Matter Annihilation Signatures from Electroweak Bremsstrahlung
• Enhancement of the annihilation of dark matter in a radiative seesaw model
• Detecting Gamma-Ray Anisotropies from Decaying Dark Matter: Prospects for Fermi LAT
• On the effective operators for Dark Matter annihilations
• Dynamical Dark Matter and the Positron Excess in Light of AMS
• Gamma-ray boxes from axion-mediated dark matter
• Indirect Signals from Solar Dark Matter Annihilation to Long-lived Right-handed Neutrinos
• Bremsstrahlung in dark matter annihilation
• Gamma-Ray Lines from Radiative Dark Matter Decay
• Enhancing Dark Matter Annihilation Rates with Dark Bremsstrahlung
• Constraints on the pMSSM from LAT Observations of Dwarf Spheroidal Galaxies
• Neutrino signals from electroweak bremsstrahlung in solar WIMP annihilation
• Leading QCD Corrections for Indirect Dark Matter Searches: a Fresh Look
• Hadronic Footprint of GeV-Mass Dark Matter
• Probing dark matter models with neutrinos from the Galactic center
• Bremsstrahlung signatures of dark matter annihilation in the Sun
• Impact of internal bremsstrahlung on the detection of gamma-rays from neutralinos
• Gamma Ray Spectra from Dark Matter Annihilation and Decay
• Radiative corrections to vectorlike portal dark matter
• Decaying Dark Matter in Supersymmetric Model and Cosmic-Ray Observations
• Vector dark matter annihilation with internal bremsstrahlung
• Electroweak fragmentation functions for dark matter annihilation
• The Role of Electroweak Corrections for the Dark Matter Relic Abundance
• The case for three-body decaying dark matter
• Dark matter annihilation with s-channel internal Higgsstrahlung
• Electroweak bremsstrahlung in bino-like dark matter annihilations
• Catching p via s wave with indirect detection
• Dark matter annihilation into gamma-ray line generated by anomalies
• Triplet Dark Matter from leptogenesis