Exciting Dark Matter and the INTEGRAL/SPI 511 keV signal

Abstract

We propose a WIMP candidate with an ``excited state'' 1-2 MeV above the ground state, which may be collisionally excited and de-excites by e+e- pair emission. By converting its kinetic energy into pairs, such a particle could produce a substantial fraction of the 511 keV line observed by INTEGRAL/SPI in the inner Milky Way. Only a small fraction of the WIMPs have sufficient energy to excite, and that fraction drops sharply with galactocentric radius, naturally yielding a radial cutoff, as observed. Even if the scattering probability in the inner kpc is << 1% per Hubble time, enough power is available to produce the ~3x10^42 pairs per second observed in the Galactic bulge. We specify the parameters of a pseudo-Dirac fermion designed to explain the positron signal, and find that it annihilates chiefly to e+e- and freezes out with the correct relic density. We discuss possible observational consequences of this model.

11 pages; v2 references added; v3 updated model to allow for single excitations and calculation of single excitation cross section; updated halo profiles; references added; conclusions unchanged

References in corpus (5)

• Forming Disk Galaxies in Lambda CDM Simulations
• The sky distribution of positronium annihilation continuum emission measured with SPI/INTEGRAL
• Microquasars as sources of positron annihilation radiation
• Effect of dark matter annihilation on gas cooling and star formation
• Searching for annihilation radiation from SN 1006 with SPI on INTEGRAL

Cited by in corpus (124)

• A Theory of Dark Matter
• Secluded WIMP Dark Matter
• First results from DAMA/LIBRA and the combined results with DAMA/NaI
• Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
• Search for a dark photon in e+e- collisions at BABAR
• CMB Constraints on WIMP Annihilation: Energy Absorption During the Recombination Epoch
• Illuminating Dark Photons with High-Energy Colliders
• Cores in Dwarf Galaxies from Dark Matter with a Yukawa Potential
• The DAMA/LIBRA apparatus
• LEP Shines Light on Dark Matter
• A Tale of Tails: Dark Matter Interpretations of the Fermi GeV Excess in Light of Background Model Systematics
• Non-Abelian Dark Sectors and Their Collider Signatures
• On possible interpretations of the high energy electron-positron spectrum measured by the Fermi Large Area Telescope
• Probing Dark Forces and Light Hidden Sectors at Low-Energy e+e- Colliders
• Cosmological constraints on exotic injection of electromagnetic energy
• Kinetic Mixing as the Origin of Light Dark Scales
• Discovering New Light States at Neutrino Experiments
• Constraining Interactions in Cosmology's Dark Sector
• Thermal Dark Matter From A Highly Decoupled Sector
• A Natural Supersymmetric Model with MeV Dark Matter
• Investigating electron interacting dark matter
• Direct Detection of Multi-component Secluded WIMPs
• New Parity-Violating Muonic Forces
• Nonabelian dark matter: models and constraints
• Signatures of sub-GeV dark matter beams at neutrino experiments
• Dark Matter Signals from Cascade Annihilations
• Hidden Sector Dark Matter Models for the Galactic Center Gamma-Ray Excess
• Testing GeV-Scale Dark Matter with Fixed-Target Missing Momentum Experiments
• Self-Scattering for Dark Matter with an Excited State
• High Energy Positrons and the WMAP Haze from Exciting Dark Matter
• The galactic 511 keV line from electroweak scale WIMPs
• Breaking the Dark Force
• Investigation on light dark matter
• DAEdALUS and Dark Matter Detection
• Exploring New Physics with O(keV) Electron Recoils in Direct Detection Experiments
• A Dark Matter Progenitor: Light Vector Boson Decay into (Sterile) Neutrinos
• Spectral distortion constraints on photon injection from low-mass decaying particles
• Self-Interacting Dark Matter through the Higgs Portal
• Circumscribing Late Dark Matter Decays Model Independently
• The Inelastic Frontier: Discovering Dark Matter at High Recoil Energy
• Galactic 511 keV line from MeV millicharged dark matter
• Strong constraints on decay and annihilation of dark matter from heating of gas-rich dwarf galaxies
• Explaining the XENON1T excess with Luminous Dark Matter
• Indirect Dark Matter Detection Limits from the Ultra-Faint Milky Way Satellite Segue 1
• Enhanced neutrino signals from dark matter annihilation in the Sun via metastable mediators
• Light new physics in XENON1T
• X-ray Lines from Dark Matter: The Good, The Bad, and The Unlikely
• Physics Motivation for a Pilot Dark Matter Search at Jefferson Laboratory
• Freeze-in Production of Sterile Neutrino Dark Matter in U(1)${}_{\mathrm{B}-\mathrm{L}}$ Model
• Metastable GeV-scale particles as a solution to the cosmological lithium problem
• Electric But Not Eclectic: Thermal Relic Dark Matter for the XENON1T Excess
• Cosmic-ray upscattered inelastic dark matter
• PAMELA, DAMA, INTEGRAL and Signatures of Metastable Excited WIMPs
• A New Direction in Dark-Matter Complementarity: Dark-Matter Decay as a Complementary Probe of Multi-Component Dark Sectors
• Self-interacting Dark Matter Without Direct Detection Constraints
• Constraints on a mixed model of dark matter particles and primordial black holes from the Galactic 511 keV line
• Low-mass inelastic dark matter direct detection via the Migdal effect
• Diffuse MeV Gamma-rays and Galactic 511 keV Line from Decaying WIMP Dark Matter
• The Positron Puzzle
• Signals from dark atom formation in halos
• Search for Dark Matter
• Inelastic Fermion Dark Matter Origin of XENON1T Excess with Muon $(g-2)$ and Light Neutrino Mass
• A Warped Model of Dark Matter
• The 511 keV Excess and Primordial Black Holes
• Origins of Hidden Sector Dark Matter II: Collider Physics
• Forbidden Dark Matter Annihilations into Standard Model Particles
• Strong Optimized Conservative Fermi-LAT Constraints on Dark Matter Models from the Inclusive Photon Spectrum
• New Pathways to the Relic Abundance of Vector-Portal Dark Matter
• Consistency of dark matter interpretations of the 3.5 keV X-ray line
• ATIC and PAMELA Results on Cosmic e^\pm Excesses and Neutrino Masses
• Nonabelian dark matter models for 3.5 keV X-rays
• On the Origin of the 511 keV Emission in the Galactic Centre
• Is There a Dark Matter Signal in the Galactic Positron Annihilation Radiation?
• Dark Matter prospects with COSI: ALPs, PBHs and sub-GeV Dark Matter
• Natural $X$-ray Lines from the Low Scale Supersymmetry Breaking
• Predictions of the causal entropic principle for environmental conditions of the universe
• Hunting for Dark Matter and New Physics with GECCO
• Direct Detection of Light "Ge-phobic" Exothermic Dark Matter
• Dark Matter from Exponential Growth
• Search for events with leptonic jets and missing transverse energy in ppbar collisions at sqrt(s)=1.96 TeV
• A Model For Late Dark Matter Decay
• Lining up the Galactic Center Gamma-Ray Excess
• Spin-dependent sub-GeV Inelastic Dark Matter-electron scattering and Migdal effect: (I). Velocity Independent Operator
• Search for Higgs bosons decaying into new spin-0 or spin-1 particles in four-lepton final states with the ATLAS detector with 139 fb${}^{-1}$ of $pp$ collision data at $\sqrt{s}=13$ TeV
• Detecting Axion-Like Particles with Primordial Black Holes
• A 3.55 keV Line from Exciting Dark Matter without a Hidden Sector
• Pushing the frontier of WIMPy inelastic dark matter: journey to the end of the periodic table
• Is the effect of the Sun's gravitational potential on dark matter particles observable?
• Utilizing cosmic-ray positron and electron observations to probe the averaged properties of Milky Way pulsars
• Astrophysical probes of inelastic dark matter with a light mediator
• The Sensitivity of Future Gamma-Ray Telescopes to Primordial Black Holes
• Optimizing Energetic Light Dark Matter Searches in Dark Matter and Neutrino Experiments
• A celestial gamma-ray foreground due to the albedo of small solar system bodies and a remote probe of the interstellar cosmic ray spectrum
• Detection of Inelastic Dark Matter via Electron Recoils in SENSEI
• Positron Annihilation in the Nuclear Outflows of the Milky Way
• Exothermic isospin-violating dark matter after SuperCDMS and CDEX
• Consequences of dark matter self-annihilation for galaxy formation
• The Morphology of Exciting Dark Matter and the Galactic 511 keV Signal
• Supermassive black hole seeds from sub-keV dark matter
• Effects of dark atom excitations
• The Effect of Multiple Cooling Channels on the Formation of Dark Compact Objects
• Revisiting GeV-scale annihilating dark matter with the AMS-02 positron fraction
• Weakly interacting massive particle cross section limits from LOFAR observations of dwarf spheroidal galaxies
• Connecting Low scale Seesaw for Neutrino Mass to Inelastic sub-GeV Dark Matter with Abelian Gauge Symmetry
• Positron excess in the center of the Milky Way from short-lived ${\beta }^{+}$ emitting isotopes
• Protecting unparticles from the MSSM Higgs sector
• Imaging the positron annihilation line with 20 years of INTEGRAL/SPI observations
• Low-Mass dark matter (in)direct detection with inelastic scattering
• Inverted dipole feature in directional detection of exothermic dark matter
• Improved measurements of the Dalitz decays $\eta /{\eta }^{\prime }\to \gamma e^{+}{e}^{-}$
• The Hydrogen Mixing Portal, Its Origins, and Its Cosmological Effects
• Neutralino Dark Matter as the Source of the WMAP Haze
• Enhancing Compton telescope imaging with maximum a posteriori estimation: a modified Richardson-Lucy algorithm for the Compton Spectrometer and Imager
• Possible counterpart signal of the Fermi bubbles at the cosmic-ray positrons
• Indirect searches for dark matter with the Fermi LAT instrument
• Darker matter generating from the dark
• Analogies between nuclear physics and Dark Matter
• Dark matter haloes in the multicomponent model. III. From dwarfs to galaxy clusters
• Reviving MeV-GeV Indirect Detection with Inelastic Dark Matter
• Illuminating long-lived dark vector bosons via exotic Higgs decays at $\sqrt{s}=13\text{TeV}$
• Earth-Catalyzed Detection of Magnetic Inelastic Dark Matter with Photons in Large Underground Detectors
• Measuring the smearing of the Galactic 511 keV signal: positron propagation or supernova kicks?
• Galactic Electron-Positron Annihilation Emission from X-Ray Binaries with Transient and Persistent Jets
• Some Aspects of New CDM Models and CDM Detection Methods