Dark Photons from Captured Inelastic Dark Matter Annihilation: Charged Particle Signatures

Abstract

The dark sector may contain a dark photon that kinetically mixes with the Standard Model photon, allowing dark matter to interact weakly with normal matter. In previous work we analyzed the implications of this scenario for dark matter capture by the Sun. Dark matter will gather in the core of the Sun and annihilate to dark photons. These dark photons travel outwards from the center of the Sun and may decay to produce positrons that can be detected by the Alpha Magnetic Spectrometer (AMS-02) on the ISS. We found that the dark photon parameter space accessible to this analysis is largely constrained by strong limits on the spin-independent WIMP-nucleon cross section from direct detection experiments. In this paper we build upon previous work by considering the case where the dark sector contains two species of Dirac fermion that are nearly degenerate in mass and couple inelastically to the dark photon. We find that for small values of the mass splitting $\Delta \sim 100\text{keV}$, the predicted positron signal at AMS-02 remains largely unchanged from the previously considered elastic case while constraints from direct detection are relaxed, leaving a region of parameter space with dark matter mass $100\text{GeV}\lesssim m_X\lesssim 10\text{TeV}$, dark photon mass $1\text{MeV}\lesssim m_{A^{\prime }}\lesssim 100\text{MeV}$, and kinetic mixing parameter $10^{-9}\lesssim \epsilon \lesssim 10^{-8}$ that is untouched by supernova observations and fixed target experiments but where an inelastic dark sector may still be discovered using existing AMS-02 data.

18 pages, 5 figures; v2: minor revisions to match published version; v3: updated direct detection and CMB constraints and corrected decay length in code, moving the region of experimental sensitivity to values of epsilon that are lower by an order of magnitude

References in corpus (18)

• A Theory of Dark Matter
• Results from a search for dark matter in the complete LUX exposure
• Secluded WIMP Dark Matter
• Dark Matter Results From 54-Ton-Day Exposure of PandaX-II Experiment
• Precise Relic WIMP Abundance and its Impact on Searches for Dark Matter Annihilation
• New Fixed-Target Experiments to Search for Dark Gauge Forces
• Stellar cooling bounds on new light particles: plasma mixing effects
• Inelastic Dark Matter in Light of DAMA/LIBRA
• Discovering New Light States at Neutrino Experiments
• Cosmological Constraints on Very Dark Photons
• Supernova Bounds on the Dark Photon Using its Electromagnetic Decay
• High-Energy Neutrinos From Dark Matter Particle Self-Capture Within the Sun
• Lepton Jets from Radiating Dark Matter
• Capture of Inelastic Dark Matter in the Sun
• Self-interacting inelastic dark matter: A viable solution to the small scale structure problems
• Dark matter in the solar system III: The distribution function of WIMPs at the Earth from gravitational capture
• Updated Constraints on Self-Interacting Dark Matter from Supernova 1987A
• The Spectrum of Darkonium in the Sun

Cited by in corpus (16)

• Dark Matter Self-interactions and Small Scale Structure
• Heating up Neutron Stars with Inelastic Dark Matter
• Powerful Solar Signatures of Long-Lived Dark Mediators
• Search for GeV-scale Dark Matter Annihilation in the Sun with IceCube DeepCore
• Neutrinos from captured dark matter annihilation in a galactic population of neutron stars
• First HAWC Observations of the Sun Constrain Steady TeV Gamma-Ray Emission
• Jupiter missions as probes of dark matter
• The Sun at GeV--TeV Energies: A New Laboratory for Astroparticle Physics
• Solar constraints on captured electrophilic dark matter
• New constraints on inelastic dark matter from IceCube
• A Solar System Test of Self-Interacting Dark Matter
• The leptophilic dark matter in the Sun: the minimum testable mass
• Neutrinos from the Sun can discover dark matter-electron scattering
• Probing the Dark Matter Capture Rate in a Local Population of Brown Dwarfs with IceCube Gen 2
• Inelastic dark matter scattering off Thallium cannot save DAMA
• Neutrinos from captured dark matter in galactic stars