Dark matter models for the 511 keV galactic line predict keV electron recoils on Earth

Abstract

We propose models of Dark Matter that account for the 511 keV photon emission from the Galactic Centre, compatibly with experimental constraints and theoretical consistency, and where the relic abundance is achieved via p-wave annihilations or, in inelastic models, via co-annihilations. Due to the Dark Matter component that is inevitably upscattered by the Sun, these models generically predict keV electron recoils at detectors on Earth, and could naturally explain the excess recently reported by the XENON1T collaboration. The very small number of free parameters make these ideas testable by detectors like XENONnT and Panda-X, by accelerators like NA64 and LDMX, and by cosmological surveys like the Simons observatory and CMB-S4. As a byproduct of our study, we recast NA64 limits on invisibly decaying dark photons to other particles.

arXiv comment5+3 pages, 3+3 figures. v2: clarifications and references added

References in corpus (26)

• The Simons Observatory: Science goals and forecasts
• New solar opacities, abundances, helioseismology, and neutrino fluxes
• Direct Detection of Sub-GeV Dark Matter
• Light Dark Matter Search with Ionization Signals in XENON1T
• Indirect Dark Matter Signatures in the Cosmic Dark Ages I. Generalizing the Bound on s-wave Dark Matter Annihilation from Planck
• MeV Dark Matter: Has It Been Detected?
• The 511 keV emission from positron annihilation in the Galaxy
• Probing Light Thermal Dark-Matter With a Higgs Portal Mediator
• Stringent Constraint on Galactic Positron Production
• Dark matter search in missing energy events with NA64
• Light Dark Matter at Neutrino Experiments
• Refined Bounds on MeV-scale Thermal Dark Sectors from BBN and the CMB
• Neutrino decoupling beyond the Standard Model: CMB constraints on the Dark Matter mass with a fast and precise $N_{\mathrm{eff}}$ evaluation
• Gamma-ray spectroscopy of Positron Annihilation in the Milky Way
• Directly Detecting MeV-scale Dark Matter via Solar Reflection
• Strong New Limits on Light Dark Matter from Neutrino Experiments
• Limits on Axion Couplings from the first 80-day data of PandaX-II Experiment
• Constraints on dark matter and the shape of the Milky Way dark halo from the 511 keV line
• Dark matter scattering on electrons: Accurate calculations of atomic excitations and implications for the DAMA signal
• Ruling out the light WIMP explanation of the galactic 511 keV line
• Interacting dark matter contribution to the Galactic 511 keV gamma ray emission: constraining the morphology with INTEGRAL/SPI observations
• Electron-interacting dark matter: Implications from DAMA/LIBRA-phase2 and prospects for liquid xenon detectors and NaI detectors
• Robust cosmic-ray constraints on $p$-wave annihilating MeV dark matter
• Soft gamma-ray background and light Dark Matter annihilation
• The central velocity dispersion of the Milky Way bulge
• Explanation of the 511 keV line: Cascade annihilating dark matter with the ${}^8$Be anomaly

Cited by in corpus (15)

• A Next-Generation Liquid Xenon Observatory for Dark Matter and Neutrino Physics
• Direct detection of dark energy: the XENON1T excess and future prospects
• Constraints on a mixed model of dark matter particles and primordial black holes from the Galactic 511 keV line
• The 511 keV Excess and Primordial Black Holes
• Self-interacting Inelastic Dark Matter in the light of XENON1T excess
• Pushing the frontier of WIMPy inelastic dark matter: journey to the end of the periodic table
• Boosted Self-Interacting Dark Matter and XENON1T Excess
• The Morphology of Exciting Dark Matter and the Galactic 511 keV Signal
• GeV Scale Inelastic Dark Matter with Dark Photon Mediator via Direct Detection and Cosmological/Laboratory Constraints
• Explorations of pseudo-Dirac dark matter having keV splittings and interacting via transition electric and magnetic dipole moments
• Dark Fluxes from Accreting Black Holes and Direct Detections
• Inelastic dark matter, small scale problems, and the XENON1T excess
• From oversimplified to overlooked: the case for exploring Rich Dark Sectors
• Putting all the X in one basket: Updated X-ray constraints on sub-GeV Dark Matter
• Darker matter generating from the dark