Anti-Deuterons and Anti-Helium Nuclei from Annihilating Dark Matter

Abstract

Recent studies of the cosmic-ray antiproton-to-proton ratio have identified an excess of $\sim$10-20 GeV antiprotons relative to the predictions of standard astrophysical models. Intriguingly, the properties of this excess are consistent with the same range of dark matter models that can account for the long-standing excess of $\gamma$-rays observed from the Galactic Center. Such dark matter candidates can also produce significant fluxes of anti-deuterium and anti-helium nuclei. Here we study the production and transport of such particles, both from astrophysical processes as well as from dark matter annihilation. Importantly, in the case of AMS-02, we find that Alfvénic reacceleration (i.e., diffusion in momentum space) can boost the expected number of $\bar{\mathrm{d}}$ and ${}^3\overline{\text{He}}$ events from annihilating dark matter by an order of magnitude or more. For relatively large values of the Alfvén speed, and for dark matter candidates that are capable of producing the antiproton and $\gamma$-ray excesses, we expect annihilations to produce a few anti-deuteron events and about one anti-helium event in six years of AMS-02 data. This is particularly interesting in light of recent reports from the AMS-02 Collaboration describing the detection of a number of anti-helium candidate events.

9 pages, 7 figures, 3 appendices, in v2 minor changes to reflect journal version

References in corpus (15)

• Searching for Dark Matter Annihilation in Recently Discovered Milky Way Satellites with Fermi-LAT
• Background model systematics for the Fermi GeV excess
• The galactic antiproton spectrum at high energies: background expectation vs. exotic contributions
• Scrutinizing the evidence for dark matter in cosmic-ray antiprotons
• Cosmic Ray Electrons, Positrons and the Synchrotron emission of the Galaxy: consistent analysis and implications
• Updated cosmic-ray and radio constraints on light dark matter: Implications for the GeV gamma-ray excess at the Galactic center
• What Does The PAMELA Antiproton Spectrum Tell Us About Dark Matter?
• The Role of Antimatter Searches in the Hunt for Supersymmetric Dark Matter
• Antiproton constraints on the GeV gamma-ray excess: a comprehensive analysis
• Deuteron and Anti-deuteron Production in e+e- Collisions at the Z Resonance
• The Gamma-Ray Pulsar Population of Globular Clusters: Implications for the GeV Excess
• A New Mask for An Old Suspect: Testing the Sensitivity of the Galactic Center Excess to the Point Source Mask
• Power requirements for cosmic ray propagation models involving diffusive reacceleration; estimates and implications for the damping of interstellar turbulence
• Characterizing the Nature of the Unresolved Point Sources in the Galactic Center
• A Systematic Study of Hidden Sector Dark Matter: Application to the Gamma-Ray and Antiproton Excesses

Cited by in corpus (10)

• Dark Matter meets Quantum Gravity
• The Return of the Templates: Revisiting the Galactic Center Excess with Multi-Messenger Observations
• Cosmic-ray database update: ultra-high energy, ultra-heavy, and anti-nuclei cosmic-ray data (CRDB v4.0)
• A common origin of muon g-2 anomaly, Galaxy Center GeV excess and AMS-02 anti-proton excess in the NMSSM
• Dark Matter Annihilation Can Produce a Detectable Antihelium Flux through ${\bar{\Lambda }}_b$ Decays
• Constraints on the antistar fraction in the Solar system neighborhood from the 10-years Fermi Large Area Telescope gamma-ray source catalog
• Cosmic Ray Antihelium from a Strongly Coupled Dark Sector
• Fireball anti-nucleosynthesis
• Enhanced cosmic-ray antihelium production from dark matter annihilation through light mediators
• Searching for dark matter annihilation in the Sun with the IceCube Upgrade