Cosmic-ray antideuterons as a signature for neutralino annihilation in the galactic halo

Once the energy spectrum of the secondary component is well understood, measurements of the antiproton cosmic-ray flux at the Earth will be a powerful tool to indirectly probe for the existence of supersymmetric relics in the galactic halo. Unfortunately, it is still spoilt by considerable theoretical uncertainties. As shown in this work, searches for low-energy antideuterons appear in the mean time as a plausible alternative, worth being explored. Above a few GeV/n, a dozen spallation antideuterons should be collected by the future AMS experiment on board ISS. For energies less than ∼ 3 GeV/n, the D-bar spallation component becomes negligible and may be supplanted by a possible supersymmetric signal. If a few low-energy antideuterons are discovered, this should be seriously taken as a clue for the existence of massive neutralinos in the Milky Way