Dichromatic Dark Matter

Abstract

Both the robust INTEGRAL 511 keV gamma-ray line and the recent tentative hint of the 135 GeV gamma-ray line from Fermi-LAT have similar signal morphologies, and may be produced from the same dark matter annihilation. Motivated by this observation, we construct a dark matter model to explain both signals and to accommodate the two required annihilation cross sections that are different by more than six orders of magnitude. In our model, to generate the low-energy positrons for INTEGRAL, dark matter particles annihilate into a complex scalar that couples to photon via a charge-radius operator. The complex scalar contains an excited state decaying into the ground state plus an off-shell photon to generate a pair of positron and electron. Two charged particles with non-degenerate masses are necessary for generating this charge-radius operator. One charged particle is predicted to be long-lived and have a mass around 3.8 TeV to explain the dark matter thermal relic abundance from its late decay. The other charged particle is predicted to have a mass below 1 TeV given the ratio of the two signal cross sections. The 14 TeV LHC will concretely test the main parameter space of this lighter charged particle.

References in corpus (10)

• Secluded WIMP Dark Matter
• A Tentative Gamma-Ray Line from Dark Matter Annihilation at the Fermi Large Area Telescope
• Particle physics catalysis of thermal Big Bang Nucleosynthesis
• Gamma Ray Signals from Dark Matter: Concepts, Status and Prospects
• The sky distribution of positronium annihilation continuum emission measured with SPI/INTEGRAL
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• PAMELA, DAMA, INTEGRAL and Signatures of Metastable Excited WIMPs
• Enhanced diphoton rates at Fermi and the LHC
• Gamma Lines without a Continuum: Thermal Models for the Fermi-LAT 130 GeV Gamma Line
• Axion-mediated dark matter and Higgs diphoton signal

Cited by in corpus (6)

• Ruling out the light WIMP explanation of the galactic 511 keV line
• Probing Charged Matter Through Higgs Diphoton Decay, Gamma Ray Lines, and EDMs
• Nonabelian dark matter models for 3.5 keV X-rays
• MeV dark matter in the 3+1+1 model
• Cosmic Microwave Background Constraints on Dark Matter Models of the Galactic Center 511 keV Signal
• Gamma Rays from Bino-like Dark Matter in the MSSM