KnowraPositroniumLinked fromLinked fromThe 9 pages that link to Positronium, each with the reason it gives.All 9Broader topic 5Compared with 4Quantum electrodynamicsBroader topic: Its spectrum and decay test QED in a two-body system made entirely of leptons.PositronBroader topic: Positronium provides a simple system for studying positron–electron interactions and annihilation.Charge conjugationBroader topic: Its charge-conjugation eigenvalue determines whether it can decay into an even or odd number of photons.Electron–positron annihilationBroader topic: Its spin configurations shape annihilation rates and photon multiplicities.Dirac seaBroader topic: Its existence illustrates the particle–antiparticle pair that hole theory helped predict.