Searching for light dark matter through Positronium decay

Abstract

A novel approach to detect light dark matter through the observation of a single photon in the decay of Positronium (Ps) is proposed. Branching ratio calculations indicate that light dark matter coupling to the Standard Model through a novel dark vector boson in the mass range m A ′ = 10–500 keV with strength ϵ = 2 × 10−5 –10−8 is well above the previously computed Standard Model background decay Ps → γ ν ν and could be sensitive to observation.