Astrophysical signatures of leptonium

摘要: More than 10^43 positrons annihilate every second in the centre of our Galaxy yet, despite four decades observations, their origin is still unknown. Many candidates have been proposed, such as supernovae and low mass X-ray binaries. However, these models are difficult to reconcile with distribution positrons, which highly concentrated Galactic bulge, therefore require specific propagation through interstellar medium. Alternative sources include dark matter decay, or supermassive black hole, both would a naturally high bulge-to-disc ratio. The chief difficulty reconciling observations intrinsically poor angular resolution gamma-ray cannot resolve point sources. Essentially all via formation positronium. This gives rise possibility observing recombination lines positronium emitted before atom annihilates. These emission be UV NIR, giving an increase factor 10^4 compared gamma ray allowing discrimination between truly diffuse emission. Analogously positronium, it possible form atoms true muonium tauonium. Since muons tauons unstable, leptonium will localised places origin. Thus tauonium can provide another way distinguish unresolved